Karma is of three kinds, viz. Sanchita or the accumulated works, Prarabdha or the fructifying works, and Kriyamana or the current works. Sanchita is all the accumulated Karmas of the past. Part of it is seen in the character of man, in his tendencies and aptitudes, capacities, inclinations and desires. Prarabdha is that portion of the part of Karma which is responsible for the present body. It is ripe for reaping. It cannot be avoided or changed. It is only exhausted by being experienced. You pay your past debts. Kriyamana is that Karma which is now being made for the future. It is also called Agami or Vartamana.
In Vedantic literature, there is a beautiful analogy. The bow-man has already sent an arrow; it has left his hands. He cannot recall it. He is about to shoot another arrow. The bundle of arrow in the quiver on his back is the Sanchita. The arrow he has shot is Prarabdha. And the arrow which he is about to shoot from his bow is Agami. Of these, he has perfect control over the Sanchita and the Agami, but he must surely work out his Prarabdha. The past which has begun to take effect he has to experience.
Actions are of three kinds, viz., good, bad and mixed. Good Karmas make you a god or angel in heaven. Bad Karmas throw you in lower wombs. Mixed actions give you a human birth.
Every work is a mixture of good and evil. There can be neither absolute good work nor absolute bad work in this world. This physical universe is a relative plane. If you do some action, it will do some good in one corner, and some evil in another corner. You must try to do such actions that can bring the maximum of good and the minimum of evil.