Can someone explain direct object vs indirect object with examples as well?

A direct object is something/someone that is doing the verb in a sentence e. g.

"Martha fried some eggs"

The verb is "fried" and Martha has fried the eggs so therefore she is a direct object.

Whereas an indirect object are nouns that identify for whom a verb is being performed e. g.

"Stan wrote a letter to his aunt"

Here, the aunt is the indirect object because the verb is being performed for her.