There are lot of software’s and services which you can use in multiple devices at the same time. One of the very common example is your email client. For example you would have been already logged on in your Gmail account in your mobile phone and at the same time you start using Gmail on your computer. People have been wanting to use such a messenger (chat application) which they could be used from multiple devices at same time. You could be using any device at a particular time and you can still message from that device.
However one problem it poses is security issue. Generally we log in to something and forgot to logout. Now it can happen with this messenger is as well. Suppose you are using Telegram on your android mobile and then you start using in on your laptop. After sometime you then move onto your desktop (may be at your office) and start using Telegram on that computer. So you are now logged in three devices.
You may would like to logout from these devices (as unnecessarily you are logged on laptop and desktop when you are not using them). Logging out from multiple device is pretty straight forward in Telegram.
When you log in from any device, you receive a message in your mobile app (in my case its the android mobile phone).
How to logout
To logout > Open the Telegram App on your mobile phone > Select Settings
Click “Terminate All other sessions” > This will close all the other logged on sessions (on every other device) > Only your mobile phone Telegram session will remain active.