Is there a automatic session recall function on Safari?

I am using Firefox and I am mad that it takes up so much RAM. I want to switch toSafari, but I want to open up my last session every time I open up Safari. However, I have not found such a function on Safari. Is there one? Can someone help me? I checked out extensions for Safari, but never found anything too sufficient.

Well in the History menu there's a Reopen all windows from last session option. I don't know if you can set it to open automatically, but it's just a click away.