AppleTalk is a protocol that was used on classic/vintage Macs (think: early/late 1980s, 1990s) to create local networks. The wikipedia page [0] has a good historical overview, including the parallel rise of ethernet / tcp/ip (which won).
[0] https://en.wikipedia.org/wiki/AppleTalk
How does TailTalk relate to this? Does it re-implement it?
How does TailTalk relate to this? Does it re-implement it?