Some define genetic mutations as any change in the genetic make-up of an individual. By this definition, you have:
Point mutations where 1 base in a gene is changed to a different one
Deletion mutations where 1 or more bases of a gene are no longer present in the gene.
Duplications where 1 or more bases in a gene appear twice in succession.
Deletion mutations can be so large that several genes or even a larger part of a chromosome are missing.
Chromosomal mutations include things like inversions or duplications, and can also include the presence of additional copies of a chromosome or absence of one copy of a chromosome.