Is there any difference among all these networks?
If i want to buy, send or swap any token, will it the matter for me choose any one network to perform the task?
Any significance?
Why are there so many networks?
Good metamask resource and list of available networks
https://chainlist.org/
"Chainlist is a list of EVM networks. Users can use the information to connect their wallets and Web3 middleware providers to the appropriate Chain ID and Network ID to connect to the correct chain."
Ethereum technology allows one wallet to work on many blockchains, because these blockchains are clones of Ethereum.