Fragmentation :-

1: fragmentation occurs in multi-cellular organisms with simple body organization.
2: in fragmentation an organism breaks into pieces and each pieces develops into a new individual . 
3: no specialized cells are involved in fragmentation .
4.
Fragmentation is limited to invertebrates.
5. Fragmentation is more commonly seen in plants than in animals (E.g. Non-vascular plants)

regeneration :-

1: regeneration occurs in fully differentiated multi-cellular organism with complex body organization.
2: in regeneration organism breaks into pieces and the pieces may or may not group up in to a new individual .
3: In regeneration, specialized cells proliferate and form a mass of cells. The cells from the mass differentiate to form different cells types and tissues
4. Regeneration is present in both vertebrates and invertebrates.
5. Regeneration is more commonly seen in animals than in plants