No "minecraft.jar" file..?

Hello.
I really want to install mods for my Minecraft, To make it less boring. I did the %appdata% > Roaming > .minecraft > bin
But the folder ALWAYS comes up with "Folder Empty"
I already tried MultiMc. Theres no bin folder in that.
I am highly confused, Please help ..if you can.. :c

What version are you playing? 1.6.x removed the minecraft.jar file. If you use forge, you shouldn't need it either.

I am using 1.7.5, The latest version. I've seen forge, I don't really know what it is/what it means.

1.7.5 does not have a minecraft .jar. It has versions, under the versions folder where you can install mods if you wish. 1.7.5, also does not have a forge version

Oh. Okay, Well thank you.

No it's not.. forge is 1.7.2.