What is karma? For example.

Buddhist theory of karma applies to everything. For example, a good-hearted person who specializes in doing good deeds, why is life so hard? There are two explanations, 1. Life is hard. I did something bad in my last life, and I will be punished in this life. 2. The hardship of life is the cause, but the effect has not yet happened. Only Buddha knows when there will be results. There are too many examples in daily life, because if you hit someone, someone will find someone to hit you. Because you have sponsored others, others will thank you when they develop. Everything has a cause and effect.