Difference between Share Vs Assign in MSCRM

SHARE	ASSIGN
User who has share privileges on entity record can share to another user	User who has Assign privileges on entity record can share to another user
On sharing the record, selected permission given to new user on that record.Here, ownership of the record remain same.	On Assigning record, Ownership will be transferred to new user
We can use Grant Access, Modify Access and Revoke Access Messages to share the records with SDK	We can use Assign Request to assigned records with SDK