Two reasons for an update, compatibility, and security.
Since you show FireFox (FF) in your pix:
Go to Tools >Add-Ons >Click on Add-Ons if it isn't already open.
At the top you will see in blue small print "Check to see if your add-ons are up to date".
Click on that, and you will be taken to a FF page that will check, and return results whether or not your plug-ins are okay or you can further research for the update.
Scroll down a bit, and it will explain what to do.
If it is one you have already been using or need I would just go ahead, and click on the gray update plugins... button.