A songline can work as a functioning map across country too vast to memorise any other way, which is part of why the practice survived without ever being written down.
Singing a route across the land
Songlines encode journeys taken by ancestral beings across the landscape, with specific features, waterholes, rock formations, ridgelines, tied to specific verses that, sung in the correct sequence, can guide a traveller across enormous distances by referencing landmarks in the order they will actually be encountered, functioning as a navigational and geographic knowledge system as much as a religious narrative.
Recognised by law, without being written down
Songlines and the country they describe have been cited as evidence in Australian native title land claims, since Australian courts have in some cases accepted continuity of traditional connection to land, demonstrated partly through such knowledge, as a basis for legal recognition. The underlying content of specific songlines, however, generally remains oral and restricted within the custodianship of the relevant community rather than transcribed for public or legal record in full.
Crossing language and country boundaries
Because songlines can run for very long distances, a single ancestral track may pass through the country and language of multiple different groups, each custodian responsible for their own section of the songline, a distributed system of shared but partitioned knowledge that requires cooperation across groups to maintain the full route rather than any single custodian holding the whole picture.