When you sign into your Google Chrome, you are using a Google Profile.  Google Profiles allow us to capture our browsing history, bookmarks, extensions, and settings across multiple devices.  Google Allows you to have multiple profiles based on how you like to organize your activity. For example, you may have a Google Profile for your personal use, and have a second Google Profile for your work use.  The videos below will help you better understanding how to manage multiple Google Profiles.