Equity? You mean equality (and that's still about rights, not pay.) Equity is just a stake in the outcome at all.
Equality: starting out at the same position, for example we have equal rights under the law
Equity: winding up at the same position, for example when everybody in a race wins the same medal, regardless of how hard they trained or how talented they are.
An apocryphal story about equity:
Equity in this context usually refers to the concept of Social Equity, which is interested in equality of outcome
https://en.wikipedia.org/wiki/Social_equity
The extent to which equality of outcome is pursued and for which groups are traditionally factors, but the overarching idea is in pursuit of equality of outcome.