OpenStreetMap way ID

A way is an ordered list of nodes forming a line or an outline, which is what a single building footprint or a street is usually mapped as.

A plain number with no fixed length, no padding and no segments. It counts separately from nodes and relations, so the same number can identify different elements of those three types.

A large or complex feature may be represented by a relation grouping several ways. Its component ways can still have their own identifiers. Where the kind is not known, use OpenStreetMap ID instead.