What is the difference between Process Builder and Salesforce Trigger?

Hi Divya,

Process Builder is a graphical representation of your process as you build it. It consists of

Criteria, Immediate and Scheduled Actions.

There are following things which can be done by process builder:

Create Records:In addition to updating a record, you can create a record and set the field values within the record.
Create Chatter Post:   Push a chatter update into Group or Feed.
Create an approval:Traditionally you needed a trigger to push a record into an approval process automatically. With Process builder, you can do this automatically based on criteria of the process.
Quickly consolidate Workflow:Quickly consolidate multiple workflow rules in one process.
Call an Apex Class:You can  call an Apex class.

A trigger is the piece of code, that is executed Before or After a record is inserted or updated.

Usually, an APEX (code) based evaluation of criteria to set off a chain of events.These events execute following types of operations

Insert, Update, Delete, Merge, Upsert, Undelete.

• In trigger, you write lengthy code while in process builder, you can perform the same task with some clicks. But, in some cases, process builder fails to do the required task. At that time, you can use trigger.
• For more information, please refer to this blog-  https://www.adhiman.com/process-builder-vs-apex-triggers-choosing-between-automation-tools/