Question

Is karma itself stored in the mind or just impressions that can lead to the fruition of karma?

Answer 1

According to what written proofs of ancient Brahmins say or what we call vedas and purans and what buddists say Karma is the sum of the persons actions in this and the previous states of existence , viewed as deciding their fate in future existences.
The word karma is derived from a sanskrit word called 'karman' which says action.effect.fate.
Karma is the doing which we do with all our senses and sometime under someone's guidance.