The "Multicall" project by MakerDAO provides you the ability to aggregate multiple constant function call results via one single call. This is very useful if you have to perform dozens of read calls but don't want to send every call separately due to rate limits and increased usage of API credits from your Ethereum Node provider (such as Infura or Alchemy).
Multicall is implemented as a Smart Contract, however there are also higher-level abstractions which make the interaction a whole lot simpler. Well known ones are multicall.js and ethcall.
- MakerDAO