An expert advisor, otherwise known in the forex world as an “EA,” is basically a small program that you install onto the MT4 platform that will automatically follow a trader’s instructions once a certain criterion has been met. See it as a trading robot. You tell it what to to do and when to do it and it will comply.
You can call it “automated trading” as you don’t even have to be touching your mouse and keyboard for orders to be entered.
The advantage of using an EA is that if you already have a mechanical system in place, you can create an EA to replicate the actions required once your system gives you a signal. This is particularly useful if you like trading multiple pairs or if you just don’t have the time to be in front of your computer to trade.