Integer and array types which are used by—but not unique to—Ethereum.

Uint represents non-negative integers of arbitrary size, while subclasses of FixedUnsigned (like U256 or U32) represent non-negative integers of particular sizes.

Similarly, Bytes represents arbitrarily long byte sequences, while subclasses of FixedBytes (like Bytes0 or Bytes64) represent sequences containing an exact number of bytes.

Finally, UintEnum is the Uint equivalent of IntEnum.