How do you switch to hardcore mode on Battlefield 3? and what is Infantry mode?

and does anyone else feel battlefield 3 is kinda cheap like black ops?How do you switch to hardcore mode on Battlefield 3? and what is Infantry mode?
In the filter, check "Hardcore." To get to the filter click multiplayer but not quick match. Infantry mode is where there aren't any vehicles. BF3 is way better than Black Ops ;)