Inbox categories, labels, and filters
If you send and receive a lot of emails, Gmail’s basic organization isn’t enough to keep you sorted and tidy — at least not without a lot of manual effort on your part. Fortunately, Gmail has advanced organization features that can help automate a lot of that and keep you straight.
For starters, Gmail’s inbox categories exist to automatically sort your email by intent. These inbox categories include Social, Promotions, and Spam, and Gmail automatically processes incoming emails and sorts them into these categories for your convenience.
Beyond those categories, you also have labels. A label is like a custom tag that lets you manually categorize emails however you want. Each label is like a folder, except you can mark an email with as many different labels as you want. Labels are navigable in the left-side panel, and labeling makes it easy to browse and find emails by type. For example, you might have labels for receipts, bills, work projects, different hobbies, etc.
Dave Parrack / IDG
One step further, you have filters. A filter is a custom rule you can create, which automatically does things to emails as they enter your inbox. To create a filter, click Show search options to the right of the search box, enter your search criteria, and then click Create filter.
For example, you might create a filter that automatically applies a certain label to all emails with a certain word in the subject line, or you can automatically forward emails to a different inbox if they come from a specific domain address.