What is the difference between Trigger and Workflow?

• Workflow: Inbuilt functionality, used on single object.
• Trigger: Used for complex business process in which multiple Objects can handle.

Examples:-

• Using Workflow, Based on the criteria we mentioned on the parent record, we can do filed update on the parent only but not on the chid object.
• Using Triggers, Based on the criteria we mentioned on the parent record, we can do field update on the child also.