HR payroll

Hi,

Can someone please tell me how a deferred tax asset arises through an example in employee benefits. 

What plan will give rise to it 1. Defined benefit or 2. Defined contribution plan.

Then, why does both assets and liabilities have both deferred tax assets and liabilities. Does this mean, per say, an DTA can be reduced through DTL relating to the same item (Asset column)? Where can I find complete information about it?

Txs