If you just look at the dictionary definitions of the word, the two are basically interchangeable.
1. any monetary aid
2. a sum of money or other aid granted to a student, because of merit, need, etc., to pursue his or her studies.
4. a foundation to provide financial assistance to students. However
, there is a different connotation to the word. Scholarship usually implies something based on merit or something that is earned or won. Grant implies something based on need.
Furthermore, to complicate things further, a research project can receive a grant which might be based on both merit and need.
But both are a source of money that does not need to be repaid
In other words, pure awesome sauce.