Hi Divya,
You can use the Process Builder to perform more actions than with workflow:
Create a record
Update any related record
Use a quick action to create a record, update a record, or log a call
Launch a flow
Send an email
Post to Chatter
Submit for approval
Call apex methods
But the process builder doesn’t support outbound messages.
Workflow does only 4 actions
Create Task
Update Fiel
Email Alert
Outbound Message
Take a look here for more information
Differences between Process Builder and other tools
https://www.oreilly.com/library/view/learning-salesforce-visual/9781785289835/ch05s02.html
Figure Out Which Tool To Use
https://trailhead.salesforce.com/en/content/learn/modules/business_process_automation/process_whichtool
Thanks,
Nikita Gupta