Karma

Karma is the Buddhist term which literally means "doing" or "action". The theory of karmic action and result is one of the foundational concepts of Buddhist philosophy and understanding this theory is considered an essential aspect of the Buddhist path. 

On a specific level, the term karma refers specifically to the intentional action of a sentient being but not the result. Karmic actions are compared to a seed that will inevitably ripen into a result or fruition. 

You may read the below definition from highly person which states the below.

"Depending on this difference in karma appears the differences in the birth of beings, high and low, base and exalted, happy and miserable. Depending on the difference in Karma appears the difference in the individual features of beings as beautiful and ugly, high-born or low born, well-built or deformed. Depending on the difference in karma appears the difference in worldly conditions of beings, such as gain and loss, and disgrace, blame and praise, happiness and misery."

 According to his view, owing to previous action men will become murderers, thieves, unchaste, liars, slanderers, covetous, malicious and perverts. Thus, for those who fall back on the former deeds as the essential reason, there is neither the desire to do, nor effort to do, nor necessity to do this deed, or abstain from this deed.

In normal sentence, all good and bad action constitutes Karma. Every birth is conditioned by a past good or bad karma, which predominated at the moment of death. Karma that conditions the future birth is called reproductive Karma. The death of a person is a temporary end of a temporary phenomenon. Though the present form perishes, another form which is neither the same nor absolutely different takes its place, according to the potential thought-vibration generated at the death moment, because the Karmic force which propels the life-flux still survives.