Process Builder is an alternate way of automating your business processes by writing code. It is an advanced version of the Workflow Rule. Process Builder is created on top of Visual Workflow and Flow Trigger (Deprecated). Whenever you create a process by using the Process Builder, it will automatically create a Flow and a Flow Trigger (Deprecated) to call this Flow; this happens behind the scenes and users don't need to interact with these Flows.

Workflow Rule comes with several limitations, for example, it doesn't have an action to update child records, post to Chatter, and create a child record. Process Builder is available for the Lightning Enterprise, Lightning Unlimited, and Developer editions. It is also available for the Lightning Professional edition with a few limitations, for example, you can only have five active processes in the Lightning Professional edition. There are a few advantages of Process Builder, as follows: