From IT Skills
core[edit | edit source]
- Nodes are points with a geographic position, stored as coordinates
- Ways are ordered lists of nodes, representing a polyline, or possibly a polygon if they form a closed loop.
- Relations are ordered lists of nodes, ways and relations (together called "members"), where each member can optionally have a "role" (a string). Relations are used for representing the relationship of existing nodes and ways.
- Tags are key-value pairs (both arbitrary strings). They are used to store metadata about the map objects (such as their type, their name and their physical properties). Tags are not free-standing, but are always attached to an object: to a node, a way or a relation.