Glossary

From OpenStreetMap Wiki
Jump to navigation Jump to search
Glossary - Other languages

±

This page contains a list of technical and colloquial terms used in and around the OpenStreetMap project. It is mainly aimed at beginning mappers, or beginners in a particular area of the project: most definitions should be two lines at the most.

A · B · C · D · E · F · G · H ·  I  · J · K · L · M · N · O · P · Q · R · S · T · U · V · W · X

Note: The list is certainly not complete, and there are many more jargon words in and around OpenStreetMap. The page titles used in the wiki are often short and sweet, with a definition appearing at the top of most pages: you may find your answer by doing a search.

Please improve the Glossary by adding terms useful to beginning mappers (especially if you are one!). If there's any term you'd like to include and aren't sure of the definition, please add it with [STUB] where the definition would be.

A

  • API: Application Programming Interface: how software speaks to other software. The OSM API or OSM Protocol allows computer programs to access the OpenStreetMap database. It follows the REST approach to web service construction.
  • area: A polygon representing, e.g., a park or a building. Areas are not a type of element in OSM, instead they are mapped as a closed ("circular") way having tags suited to areas. Complex shapes (with holes in them) can be mapped with multipolygons.
  • area of interest (AOI): The region, big or small, in which you map or pay close attention to the map. In a Tasking Manager project or MapRoulette challenge, the geographic region in which the project operates.
  • armchair mapping: The act of editing the map without surveying (without leaving your chair). This is often done by referencing aerial imagery.
  • attribute: In the real world, the properties of a real-world object. In the database, positions are encoded in the geometry of elements. Other attributes, such as type of object or visibility, are encoded with tags.
  • ATYL, any tags you like: A guideline that allows users to freely invent new tags for objects that are verifiable and mappable in OpenStreetMap but for which there is no existing tagging scheme yet.

C

  • cadastre: An official index map showing the location and extent of plots of land ('parcels') along with their ownership. For the UK example, see INSPIRE.
  • Carto: See OSM Carto
  • centroid: A mathematically derived point at the center of an area, often used by renderers to place labels. An area's centroid is not guaranteed to be inside it, especially in the case of multipolygons or horseshoe-shaped areas. See Wikipedia.
  • changeset: A group of edits made by a single user over a certain (short) period of time.
  • closed way: A way that ends where it begins, like a snake eating its tail. A closed way may represent
(1) a linear feature that also ends where it begins (such as a road forming a roundabout, which is tagged with highway=* and junction=roundabout); or
(2) an area feature (such as a sports pitch, leisure=pitch).
Which of these two, is determined by the way's tags: if it has tags that denote an area feature, it's an area.
  • contributor: Someone who contributes edits and improvements to the map and other OSM projects. (Someone like you!) People who contribute by editing the map are also called mappers.
  • consumers: See data consumers.
  • CWG: Communication Working Group, a committee of the OSM Foundation dealing with the press and getting the word out about the current affairs, goals and future of the OSMF and the OpenStreetMap project.

D

  • database: Where OSM's underlying map data is kept. In simple terms this means information about what things are where in the world; technically a PostgreSQL installation running on various servers, but most applications access it via the API.
  • data consumers: The people and organisations who use the OpenStreetMap data.
  • data item: Special wiki pages containing structured information about tags that is readable for machines and humans. Their page name is Item:Q followed by a number. E.g. Item:Q104 for bridge:movable=*. You can find a link to the data item in the side bar of a key's or tag's wiki page or, on mobile, in the "More" menu at the top of the page. For information about the status about the data items project, see the page Data items.
  • data primitive: An obsolete term (in OSM) for element.
  • data users: See data consumers.
  • DWG: Data Working Group, a committee of the OSM Foundation dealing with copyright infringement, imports and vandalism.

E

F

  • feature: A physical element in the landscape that can be mapped.
  • FLOSS, FOSS: free/libre and open source software: software that falls under both of these definitions.
  • Foundation: See OSMF.
  • free software (also libre software, FOSS or FLOSS): Software that is distributed with the permission to (0) use it for any purpose, (1) study and modify its source code, (2) share it, and (3) share modifications (the "four freedoms"). Similar to open source, but places emphasis on the ethics of software commons. Not all free software is available free of charge; the "free" stands for "freedom", not price. See Free software on Wikipedia.

G

  • Galileo: A GNSS funded and supported by the European Union, through the European Space Agency. See also Galileo (satellite navigation) on Wikipedia.
  • geocoder: A piece of software that converts a textual description into geographic coordinates. See also Address geocoding on Wikipedia.
  • GIS: Geographic Information System. See also Geographic information system on Wikipedia.
  • GLONASS: a GNSS developed by the Soviet Union, now run by Russia. Due to the geography of Russia, it has been designed to provide better accuracy at high latitudes than GPS.
  • GNSS: Global Navigation Satellite System, generic term for systems like GPS, GLONASS and Galileo which use signals from satellites to establish where you are.
  • GNSS tracelog, GNSS trace, GPS trace, GPS track or variants thereupon: A time series of location points recorded by a GNSS receiver, which show the route taken. See Recording GPS tracks.
  • GPS: Global Positioning System. The GNSS built and run by the government of the USA.
  • GPS unit: A GPS receiver.
  • GPX: GPS Exchange Format: an XML format used to represent data collected by GPS units. The OSM server accepts tracelogs in GPX format.

H

I

J

  • Java may refer to these terms:
  • Java Applet: In an OpenStreetMap context you may hear mention of "the Java applet" referring to a very old editing interface which used to appear on the OpenStreetMap.org site, but which was superseded by Potlatch and later iD.
  • JOSM: The Java OpenStreetMap editor. It is a map viewing and editing tool originally written by Imi. It will run on most computers and allows a user to view, edit and upload data to the OpenStreetMap database.

K

  • key: The first part of a tag, which has an associated value.
  • key=value (also key/value pair or k=something v=something else): See tag.

L

  • layer: (1) A specific rendering available in software or a website for viewing the map. (2) A key to describe the vertical relationship of overlapping elements; see layer=*. (3) One set of elements or imagery in an advanced editor such as JOSM. (4) Internal structure in a piece of rendering software.
  • libre software: See free software.
  • licence: Usually the User Licence, the terms under which anyone can use OSM and its data. Sometimes refers to the Contributor Terms under which contributors licence their work to OSM and to the world in general.
  • local traffic: Vehicles whose destination or point of origin is in the given area.
  • LWG: Licensing Working Group a committee of the OSM Foundation dealing with licencing and legal matters.

M

  • the map: Strictly, the database (unreadable by humans) of all OSM data. Also used in the conventional sense, i.e., a visual representation of real-world geography. (Check the context.) The map can be consulted in a variety of places and software and can be edited with any of several editors.
  • map features: Physical features on the ground, that are represented in OSM.
  • Mapnik: A GIS library; i.e., a collection of computer code that does things like reprojecting and rendering geo-spatial data. OSM uses Mapnik to generate tiles for the slippy map.
  • mapper: A contributor who contributes by mapping.
  • mapping: Editing the map. These edits may be based on surveys, aerial imagery (armchair mapping) or other sources. "Mapping" may also refer to the act of surveying.
  • mapping party: An event where you survey or map in group (very nice!) Upcoming mapping parties can be found under Current events.
  • markup: A very simple computer language that allows an author to use special characters (e.g., ' / < >) to tell a computer how to display some text. Many different markup systems are in use across different OSM channels: it's optional, so don't let it put you off contributing!
  • multipolygon or multipolygon relation: a relation describing a complex polygonal shape. It is used for instance when you want to map an area with a hole in it.
  • MUTCD: The Manual on Uniform Traffic Control Devices. The standard for traffic signs in the United States, with counterparts in several other countries, which differs markedly from the Vienna Convention.
  • MWG: Membership Working Group, a committee of the OpenStreetMap Foundation that deals with the membership register and fees, as well as promoting membership.

N

  • NMEA: Format used to represent data collected by GPS units.
  • node: The simplest of the three types of elements. Many nodes exist solely to encode the geometry of one or more ways that use them, in which case they don't have tags. Other nodes represent point features such as post boxes (standalone or as part of a way) or street crossings (always as part of a way). Technically, a node is an element that has a latitude and longitude in WGS84, a list of tags, and some metadata.
  • note: A comment that can be added to the map on the home page to inform of an error or something missing on the map.

O

  • object: Often used synonymously with elements, but can also refer to other technical concepts (ambiguous).
  • OGC: The Open Geospatial Consortium (http://www.opengeospatial.org/). A non-profit body that defines standards for the use and storage of geospatial data.
  • open: We try to do everything in the spirit of openness. Our maps are "open" in that anyone can use them (licensing issues notwithstanding), anyone can see how they were created, anyone can participate in that process. In addition most of our software is open source and free/libre software, and allows software developers to participate in developing the project in that way.
  • open source (also OSS, FLOSS, FOSS): Software which is distributed with the permission to i.a. modify and redistribute its source code. Inspired by and similar to free software, but places emphasis on the practicality and technical superiority of this development model, rather than ethics of user freedom. Open source is not commonly abbreviated as "OS", which would be confused with operating system or Ordnance Survey, so better use one of the other abbreviations.
  • operating system: Software such as Linux, macOS, Windows or Solaris for low level management of a computer system. Hand-held devices also have one. In the UK, its abbreviation OS could be confused with Ordnance Survey.
  • Ordnance Survey: UK government mapping agency, with extremely detailed maps collected and funded by the taxpayer... and then sold back to them at prohibitively expensive prices. Its abbreviation OS could be confused with operating system.
  • OS: May refer to either operating system or (in the UK) Ordnance Survey.
  • OSS: Open source software.
  • OSGeo: The Open Source Geospatial Foundation. Promotes the development and use of Open Source, community-based Geospatial software.
  • OSM: OpenStreetMap. This whole project. See About.
  • OSMF: OpenStreetMap Foundation, a registered not-for-profit company which supports the OpenStreetMap project and serves as its legal identity.
  • .osm: The XML format that is produced by the OSM server. It is used for communication with the API and is one of the formats that the planet dumps are available in.
  • OSM Carto: The 'standard' rendering of the map used on the website openstreetmap.org. N.B., it is not an 'official' rendering (there isn't one), but influential nevertheless.
  • Overpass API or Overpass: A read-only API allowing human beings and machines to interface with the database. Allows for almost any analysis of the map database. Used by contributors (to check for mapping errors) and data consumers alike.
  • Overpass Turbo: A browser-based tool that makes it easier for humans to use the Overpass API. Available at overpass-turbo.eu.
  • Overpass Turbo Wizard: A tool that lets you build Overpass queries more easily than writing the query yourself.
  • OWG: Operations Working Group: A committee of the OpenStreetMap Foundation that deals with the running and budgeting of the OSMF servers.

P

  • parameter: [STUB]
  • parcel: (legal or official) A piece of land with defined boundaries. Parcel data may be available from governments to help with mapping.
  • planet.osm: A regularly produced export of all nodes, ways and relations in OpenStreetMap, in one single file.
  • plugin (JOSM term): A smaller piece of software that expands the capabilities of a larger application, in this case, JOSM. See JOSM/Plugins.
  • PostGIS: http://postgis.refractions.net/ An extension to the PostgreSQL database that allows it to store OGC Simple Feature Specifications compliant objects. PostGIS is used by OSM along with Mapnik to generate tiles for the slippy map.
  • Potlatch: An older editor; Potlach 2 had iD's position in the browser, while Potlach 3 was developed as a standalone application with OSMF support.
  • preset: A user-customised list of tags from a pre-existing category, that can be quickly added to an element during editing. (Used in JOSM and iD alike, in slightly different ways.)
  • projection: A method of translating the roughly spherical surface of the earth to a flat display. The standard projection of OSM material is Plate Carree (no transformation, EPSG:4326). The standard projection for rendering OSM data onto map tiles is Spherical Mercator (EPSG:900913).
  • protocol: May refer to the OpenStreetMap API or any other protocol used by software.

Q

  • query: If you want information from a human being, you ask them a question. If you want information from a database you send it a query.
  • query language (QL): Computers don't speak human languages, so your queries must be sent in a language the computer understands: in OSM this is usually Overpass QL. Queries consist of a limited set of pre-defined operations which a query server can use to locate data which meet certain criteria.

R

  • redaction: An administrator action that makes a version of an element, or the element's entire history, inaccessible to normal mappers and the public. This can be done, for instance, when confidential information had been leaked to OSM. The most famous redaction is the big one in 2012, where the contributions were redacted of users who did not agree to the new OpenStreetMap contributor terms and license change to Open Database License (ODBL). See [1]
  • regex or regular expression: Roughly, a pattern. These are used in an Overpass query when you want to find any and all strings that match the pattern you specify.
  • ref: A tag used to enter reference numbers to objects, usually from official sources. For example, all parts of the motorway that runs from London to Cambridge get the tag ref=M11. See Map Features.
  • relation: The most complex and abstract of the three types of elements. As beginning mapper, you will likely not need to manually edit relations. Relations are used to represent features or concepts that a single node or way cannot encode, such as areas with holes in them, bus routes or turn restrictions. Technically, a relation is an element that has an ordered list of other elements (each of which may have an associated "role"), a list of tags, and some metadata. A role is a standardized piece of text that describes the function of the element within the relation, such as Role inner or Role outer on multipolygons. In some complex cases, relations can also contain other relations. Relations are not categories.
  • REST: Web development paradigm which we adopt with our protocol interface (API). It means we make objects available at unique URLs, and follow standard use of HTTP protocol features.
  • revert (see Category:Revert): May refer to undoing deletions and partial or complete changeset rollbacks.
  • router: A service/device for working out a route between two geographical points using OSM or other map data (often for use as a navigation aid).
  • rendering:
    • (as a noun) A visual representation of the database (which is itself a coded representation of 'on-the-ground' features). One set of data can be presented (rendered) in different ways: e.g., using different colours and fonts, or showing/suppressing different features.
    • (as a verb) The process of turning raw geospatial data into a human-usable form. Usually the that form is a visual representation: a 'map' in ordinary language.
  • renderer (see Category:Renderers): Any piece of software that renders the map database into usable form. Usually this means as image files analogous to a traditional paper map, but routers and other specialist software are also renderers.
  • The Rails Port: OSM core components: The protocol interface (API) and the front end website components are often referred to as as "The Rails Port" because there was a large development effort to migrate the software to the Ruby on Rails web development framework. Prior to this, the OSM internals were implemented as a standalone program in the Ruby language.

S

  • segment: Segments were one of the types of elements in old versions of the OSM API.
  • SiRFstar III: A GPS chipset by SiRF Technologies.
  • slippy map: The word 'slippy' (rather than 'static') is used to highlight that a map image can be dragged around, allowing a user to see what's off the edge of the display.
  • SotM: State of the Map: The annual, international conference of OpenStreetMap, organised by the OpenStreetMap Foundation. Also the name for local conferences, organised by local teams and not the OSMF. An example of this is SotM Europe.
  • string: Any sequence of letters and numbers that a computer program treats as a unit. May have a natural language meaning, a computer language meaning, both, or neither.
  • survey: Collecting information to map by walking, cycling or driving around and observing. This is in contrast with armchair mapping techniques. You can record your observations to map them later at home or use a mobile editor on a handheld device to map in the field. See the page Mapping techniques.
  • SVG: Scaleable Vector Grapics. XML format for representing vector graphics. SVG maps can exported using the export tab, or created by Osmarender.

T

  • tag: A representation of an attribute of some object in terms that the OSM database can store. Tags are added on elements and on changesets. Each tag is a key=value pair. E.g., an element in the database may have the tags amenity=school and name=Mahatma Ghandi Middle School, where amenity and name are keys and school and Mahatma Ghandi Middle School are values. Most of the pages you will visit on this wiki are there to describe which tags to use in OpenStreetMap. See the page Tagging describes adding tags to elements.
  • tagging scheme (also schema): An established system for tagging a particular class of object. The Seamark Tagging Schema is a good example - although other schemes are much less complex than that one.
  • talk page: A page for talking about a "main" page. E.g., this page is the Glossary. To talk about what's here, you can visit Talk:Glossary. Not to be confused with a user talk page. See also Wikipedia:Talk page on Wikipedia.
  • template: In the wiki, a template is a piece of wiki markup that makes text display (render) in a special way (e.g., it may be in a different font). Using a template on a page is called "transcluding" a template: not only is it included, but it can later be changed centrally across (trans) all pages where it is found. See the MediaWiki manual: mw:Help:Templates.
  • tiles: Small image files that make up the slippy map. So called because of their arrangement in a grid.
  • trace: (noun) Usually refers to a GPS trace, as on the website: traces. For the verb, see tracing.
  • tracing: (1) Following features visible in aerial imagery to add objects to the map (e.g. "tracing a building outline"); (2) Creating traces with a GPS receiver.
  • transclude: See template.
  • track: (1) A GPS track. (2) A type of rough road, a cycle track, a railway track or a racing track (see Track).
  • tracelog or tracklog: See GNSS tracelog.
  • transit traffic: Vehicles which are only passing through a given area without stopping in it.

U

  • user ID: Strictly, an OSM user's unique identification number. May also refer to a user's user name. Every OSM user has one of each: the numerical user IDs are usually hidden, but are used in some downstream services as a more reliable identifier (they can't be changed).
  • user name or display name: The name you use to log in to OpenStreetMap. It also appears on your profile page, and in your profile page URL.
  • user talk page: A place where others can talk to you, in public, by posting messages to your personal page. The page address is User talk:<YourUsername>. Don't confuse it with a talk page.

V

W

  • way: One of the three types of elements, used to represent a linear feature (such as roads or fences) or an area (such as buildings). A way represents an area if it both (1) is closed and (2) has tags denoting an area feature (such as building=yes). Technically, a way is an element that has an ordered list of nodes, a list of tags, and some metadata. Ways are continuous (they cannot have breaks) and non-branching.
  • wiki: A website that anyone can edit, not just someone "official". See also here.
  • the wiki: This website, wiki.openstreetmap.org. The main reference point for information on everything in OSM. Mostly describes best/accepted practice but not always, and definitely not 'the last word'.
  • WGS84: The geodetic datum that GPS is based upon. All geodata in OSM uses WGS84. This can be very different for geodata gathered from other sources. For example the Royal Observatory in Greenwich is at 0°0'0"E in the ellipsoid for OS maps, but at 0°0'5"W in WGS84.

X

  • XML: eXtensible Markup Language, a markup language that is used for encoding information in documents.

See also

External resources

Retrieved from "https://wiki.openstreetmap.org/w/index.php?title=Glossary&oldid=2797497"