What happened to captured tanks in war?

 

During the Second World War, some tanks were often captured by either side for probably two reasons:
Modifications and improvements of the tank or for the advantage of using a powerful machine on the battlefield.

The tank that we see in this image is a Russian KV-1 tank which was reportedly captured by the Germans and later fitted with upgrades to its armour and gun.
These upgrades fixed the flaws of this old tank and made it a much more formidable opponent than how it was before being captured.