Is assignment and nomination of the LIC policy is one of the same thing?
There are two kinds of assignments
1. Absolute Assignment
2. Conditional Assignment
Absolute Assignment:
In an absolute assignment, all rights on the policy both maturity and death benefits are transferred to the assignee. Example if you as a proposer made an absolute assignment, say as a gift to a friend, then the all rights on the policy are transferred to your friend. The assigne receives the maturity and death benefits. The proposer which is you, will lose all legal rights on your policy. You cannot revert back an assignment. Any changes thereafter can only be done by the assigne which is your friend.
Conditional Assignment:
Conditional assignment has some conditions and clauses attached to the assignment. The assignment is only valid as per the condition.

Absolute Assignment is used in case of gifts.
Conditional Assignment is used in case of mortgages,etc.