Term s PInteger has a convenient Num instance that allows you to construct Plutarch level integer terms from integer literals. It also means you have all the typical arithmetic operations available to you:
1 + 2where 1 and 2 are Term s PIntegers.
Alongside Num, it also has a PIntegral instance, allowing you to use division, modulus etc.
It also has a PEq and POrd instance, allowing you to do Plutarch level equality and comparison.
It does not have a PlutusType instance.
This is synonymous to Plutus Core builtin integer.