Since gadgets getting cheaper and crucial day by day, we don't just use a single gadget for all occasions, nevertheless, we use the same email ID to log in into all these devices. But we don't log into email accounts with our device alone, sometimes we may leave our device at home or somewhere else, so we seek a public internet cafe, friend's device and so on. We all have the habit of just closing the browser window without signing out of any online accounts, however, it doesn't matter when you do it on your private computer networks. But sometimes we do the same on the public internet as well, so this could be the worse thing than letting a stranger into our home. See Also: How to Check whether Email ID exists on the domain and Valid (or) not How to Sign Out of Your Gmail Accounts On All Device Remotely From Other Computer? Whenever you log-out from any one of Google services, it will automatically sign-out you from all other services synchronized with it