What are the actions in workflow?

Workflow lets you automate standard internal procedures and processes to save time across your org. Many of the tasks you normally assign, the emails you regularly send, and other record updates are part of your organization’s standard processes. Instead of doing this work manually, you can configure workflow rules to do it automatically.
Workflow rules can be broken into two main components.
Criteria: the “if” part of the “if/then” statement. In other words, what must be true of the record for the workflow rule to execute the associated actions.
Actions: the “then” part of the “if/then” statement. In other words, what to do when the record meets the criteria.