FICA

So ive been working a bit now as a truck driver and my employer just started taking out FICA taxes out of my paycheck.
I dont recall ever paying this type of tax in any other type of job i had and i wanted to get a better understanding of it in simple terms.

I am already paying federal taxes and state taxes and now am paying fica also.

I googled it but it gives me a bit of a broad definition.
I really want to know if i have to pay into it as a truck driver, Does it benefit me in anyway?
What the heck is it, and why have i never had to pay it before?

 

O ok i guess its just worded differently on my pay history.
Im used to seeing social security. Ive never seen it say fica.
That explains it.
Railroad professions dont pay into social security?