Frontier: What is trait LinearCostPrecompile about?

Question

So it's often seen in Precompile implementations as a trait bound :

impl<T: LinearCostPrecompile> Precompile for T {

and the trait itself :

pub trait LinearCostPrecompile {
    const BASE: u64;
    const WORD: u64;

    fn execute(
        input: &[u8],
        cost: u64,
    ) -> core::result::Result<(ExitSucceed, Vec<u8>), PrecompileFailure>;
}

Can someone explain the why and what of this trait?