You may have used a Google Account to sign in for any of your Google services on the web. If you already have a Google Account, you can also use it with your Android devices to open documents, read emails, and access most Google Drive.  But having multiple google accounts can cause you confusion when opening different software or apps. To fix this, you need a Link Handler.

What is Link Handler?

This is a plug-in for any browser.  You can use this on any browser, as long as the browser you use supports web apps. This extension separates your personal account, work account, and other Google account for easier access.