Expert advisor (EA) is a program based on a strategy. Most of the EAs r available for MT4 platform. To use them, u need to put EA file into MT4 EA directory which u can easily find by googling. EAs do trading for u.

To use an EA u just need to enable EA on the chart where u want to use it. You can also find a lot of videos and articles on how to use EA. 

Advantage can be accuracy, no effect of emotional factors and greed, 24/5 trading.
Disadvantages can be if EA is bad, it can blow ur account. It is hard to find a good EA. 

Originally posted by bbasiit123

Please  i m new in forex so want to know what are expert advisors and how to use them? do they do trading for us? what si its advantage?

Looks like u r a newbie. But ur posts on other threads dun support this statement. It seems u have good theoratical knowledge of forex.  Your question is well answered by jogi. 

I want to advise one thing. NEVER buy an EA from any website.

Originally posted by bbasiit123

Please  i m new in forex so want to know what are expert advisors and how to use them? do they do trading for us? what si its advantage?

 

Do u have any expert advisor? or r u planning on buying one? As u dont know much about EAs, I recommend u to take opinions of different users here about the EA u r planning to buy.

Originally posted by bbasiit123

Please  i m new in forex so want to know what are expert advisors and how to use them? do they do trading for us? what si its advantage?

 

There r 2 types of expert advisors. automatic and semi automatic. Automatic EAs will do trading 24/5 for u once u set it up.

Semi automatic EAs need some manual work.