Karma is defined in the English dictionary as
(Hinduism) The sum total of a person's actions, which determine the person's next incarnation in samsara, the cycle of death and rebirth.
A force or law of nature which causes one to reap what one sows; destiny; fate.
(uncommon) A distinctive feeling, aura, or atmosphere.
(internet) A score assigned to a user of a discussion forum, indicating the popularity of their posts with other users.
Destiny on the other hand is defined as:
That to which any person or thing is destined; a predetermined state; a condition predestined by the Divine or by human will
Synonyms: fate, lot
The fixed order of things; invincible necessity; an irresistible power or agency conceived of as determining the future, whether in general or of an individual.
Synonyms: fate
So what do you believe in? Is the question. Some people believe someone's fate is determined by how he lives his life, others think the sins of one will likely catch up with him some day (karma) or live on through his generation.
Personally, I think karma is real and so is destiny. I am bound to do great things and that's my believe. I live carefully to not create demons that will hunt me or my family in the nearest future,now that's fear of karma. I was taught that the demons you create today, or better still the hate you give today will surely come back to hunt you tomorrow, but beyond reasonable doubt I have seen it happen to many people who one will say deserve it, others might feel pity.
Destiny and karma are probably intertwined. My mom says that destiny can be delayed but not denied, and if you do someone bad today, be sure to not cry when it is reciprocated.
Source
My mom told I and my siblings about a man in my village who was a wicked witch doctor, the mere sin of passing without greeting him might get on his nerves and make you fall I'll if not do worse.His acts continued for while and one faithful day, he was returning from God knows where and all they heard was a loud scream, he was lying helplessly on the ground, knowing it was the witch doctor, everyone passed leaving him there. The next morning he was dead and all the people felt was joy. Some said he might have touched what or who he shouldn't have. Others said the evil he has committed has caught up with him. So yes karma and destiny can work together,or better still be true. Legends have given us several tales, movies have shown us, live has proven it to us...