Erc1155 tokeId and token typeId seems to be confusing

I'm trying to explore erc1155 with knowledge of erc721. I come to know that in erc1155, the id refers to the token type. I found this from

The only difference in ERC-1155 is that we pass the values as an array and we also pass an array of id's. For example given ids=[3, 6, 13] and values=[100, 200, 5], the resulting transfers will be

Transfer 100 tokens with id 3 from _from to _to.

Transfer 200 tokens with id 6 from _from to _to.

Transfer 5 tokens with id 13 from _from to _to.

it seems confusing to me that a token with id consists of 100 tokens? what does that mean id here?

and something more interestingly, They mention metadata uri should consists id substitution. which id do they refer to? token type Id? or token Id(I believe there will be no token Id for each and every token in supply)

The URI value allows for ID substitution by clients. If the string {id} exists in any URI, clients MUST replace this with the actual token ID in hexadecimal form. This allows for a large number of tokens to use the same on-chain string by defining a URI once, for that large number of tokens.

in erc721, each token will have an id and it will have its own metadata URI. How about ERC1155? will metadata URI refer to the batch tokens?

can anyone please give me a context on these?