Uhm, yeah. So uh....
Basically people use it to differentiate between slow passionate sex and all-out feral sex. I see people talking about whether or not they're in love with the person, or if the other person cares about what you're having.
I can't speak for every guy but caring whether or not your partner is having a good time pretty much applies at all times for me.
And the definition basically varies between women, as women vary immensely in what they like, what feels good, and what doesn't. IE: some women like having their cervix slammed into until they cramp up, and some don't. Most women can't orgasm from vaginal sex, but some can.
Pretty much ramming is what it implies. To paraphrase Tenacious D, it's what you do after you ball your woman discretely, you fsck them hard.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."