Reincarnation is Hindu belief that

Reincarnation, a major tenet of Hinduism, is when the soul, which is seen as eternal and part of a spiritual realm, returns to the physical realm in a new body.

Reincarnation in Hindu belief is when the soul, returns to the physical world in a new body, but how they acted while alive will affect how their next life is, for example, a horrible king might be a peasant in his next life, but a soldier who sacrificed himself for the great or good would come back as a king. something else to know is that you can only go up or down the reincarnation poll so much, eventually you will reach heaven or be turned into dirt, because karma affects how you will come in the next life.