When you want to send emails via a workflow rule and an email alert, you will need an email template. You can use merge fields on email templates to dynamically pull in data from Salesforce into your email message.
Now that we have created an email template, we are now going to create an email alert to associate it with.
An outbound message sends information to a designated endpoint, like an external service.
Resource:
Outbound Message Actions - https://help.salesforce.com/articleView?id=workflow_managing_outbound_messages.htm&type=5
Approvals take automation one step further, letting you specify a sequence of steps that are required to approve a record.
Resource:
Approvals - https://help.salesforce.com/articleView?id=what_are_approvals.htm&type=5