Karma has a cosmic as well as psychological aspect. Every deed must produce its natural effect in the world; at the same time it leaves an impression on or forms a tendency (samskara) in our mind, which inclines us to repeat the deed we have once done.
All deeds have fruits in the world and effects on the mind. For an individual, the impact of karma at a gross level is manifested in the physical world and at the subtle level in the mental world, influencing a person's psyche as well.
All the forces of nature whether physical or mental obey the law of cause and effect. No event can occur without having a definite cause behind it.
Every effect must have a cause, every consequence must have an antecedent, so also there must be equal balance between a cause and its effect.
Every action you perform is like planting a seed. The life you experience tomorrow grows from the seeds you plant today.
