olemus
kontekstist sõltuva sisuga kiht mõnedes mudelites (NB! mitte OSI ega TCP/IP-mudelis)
= a context-dependent layer in some models (not in OSI or TCP/IP)

näiteid
https://www.grazitti.com/blog/how-to-leverage-data-layer-with-google-analytics/
https://www.simoahava.com/analytics/data-layer/
https://segment.com/blog/what-is-a-data-layer/
https://developer.android.com/topic/architecture/data-layer