Android skillfully using the Finish method

In Android app development, when we jump from one activity to another, I use intent;

Eg:intent Intent = new Intent (a.this,b.class);

StartActivity (Intent);

To do so, when we successfully jump to B, when we click on the function menu to return, I successfully returned to the activity of a.

Eg1:intent Intent = new Intent (a.this,b.class);

StartActivity (Intent);

Finish ();

To do so, when we jump from A to B, we click the Back button and our activity jumps to the activity before a.

So when do you add the Finish method?

Business Scenario: For example, in the order list a click New order to enter New Order B activity, click Save, jump to Order details C, in c I click the Back button I want to

Let him return directly to a, so this business scenario EG1 can fulfill our needs.

Android skillfully using the Finish method