2.17 ABI Encoding & Decoding

Solidity supports multiple functions in these categories. The obvious ones are the abi.encode() and abi.decode() functions that take arguments and encode them or decode them, specifically with respect to the ABI.

There are also functions that encode with the function selector (abi.encodeWithSelector()) or with the signature (abi.encodeWithSignature()), and finally there is abi.encodePacked() which takes the arguments and performs the encoding in a packed fashion ( there's no padding applied between the arguments supplied).

For this reason the packed encoding can be ambiguous. This is something that affects security when you're considering these functions, specifically this abi.encodePacked() function.