a crypto being on a stake it means that this crypto is mining others?
In a sense, yes.
You are securing the network by contributing to transaction validation, and the consensus mechanism is based off people showing that they have an active stake in the network as opposed to they are expending significant energy.
So it's really the same concept but in a different form. Staking is NOT yield farming or interest generation per se, which is what some people seem to be confused about.