In the context of Algorithm Analysis, what is the meaning$/$use of the term parameterization?

Only function parameters affect the time cost of an algorithm, so we need to treat the parameters in a special way.

The time cost of an algorithm is expressed as a function of the size of the input.

The size of the input for an algorithm doesn't matter, so we replace it with a variable.

We represent the size of the input as a parameter, so we know how much memory the algorithm will consume.