Are there indicators for the token type in pool data?

[ruidazeng]

I am trying to understand how to identify the specific tokens involved in a pool within an AMM. For example, how do we determine whether the pool is trading token A or token B?

In real-world scenarios, this would apply to identifying crypto tokens in pairs such as ETH/DAI: What attribute in the pool data indicates which token is ETH and which is DAI? Or is this inferred somewhere else.