Process Builder is a workflow tool that helps automate business processes without writing a single line of code. For example, imagine that a company you do business with (which we call an Account in Salesforce), changes its location. You’d want a way to automatically update the business address of all the people that work at that company (your Contacts).
In this Quick Start, you’ll do exactly that: create a new process that updates Contact records whenever the Account billing address changes. As you’ll see, it’s quite easy, and doesn’t require a shred of code.
You first create a process and then select the object on which the process runs. You also make sure the process kicks off whenever a record is edited, because you’re going to change the business address in a moment.
Builderin the Quick Find box, and select Process Builder.
Contact address change
6. Click + Add Object.
7. In the right window, select Account from the Object drop-down list.
8. For Start the process select when a record is created or edited.
Also you can add the criteria by clicking the + symbol and set the criteria name,criteria for executing action and conditions then click save.
you can also add the immediate action,see the below picture,
This training information is very useful to learn about process builder.