Hi @aseelvn07,
yes they sound similar, but are different.
we can say that Delta work on target side, Optimization on Sailpoint side.
With the Delta, IIQ request only changed object to the target system.
With Optimization, IIQ recive all the data but work only on changed object.
For example, if you 50k account on AD but only 5k are changed, with delta IIQ receives the only 5k; with Optimization, IIQ receives 50k but will work on 5k.
You can use both for improve the performace.
PS Delta is not avaible for all target system or you must work on target system before the activation(ex. JDBC)