James Gee; Semiotic Domains and learning and literacy

I've just started getting to grips with this: I think the Semiotic Domain looks very similar to communities of practise, I wonder which came first,  but essentially its the time old nerdy pursuit of all boys together in the motorcycle club, we all like motorbikes so we go to a club house where we can get to know us, the bike better and discuss how to adjust the Norton Comando clutch spring...  the learning and literacies are expanded by the community and interest... watch this space I may have got this wrong..