Yes it does, based on a summoning system. Probably better off asking Shepenewet or someone else for details on that, I've always gone solo.

*Summoned phantom Shepenwepet*
Yep, there be co-op in Dark Souls 2. You need an item that you get early on, so you can't instantly team up with buddies, but it's not long before you can. You have to be human to summon help, so if you die you have to remedy that with specific item OR (unless this was patched, I forget) allow yourself to be summoned by others and help them defeat a boss. You don't need to be human to be summoned yourself. Once you get the White Sign Soapstone, all you have to do is use it and plunk your summon sign on the ground where people will see it, and wait.
Having played the entirety of the original Dark Souls solo (Solaire doesn't count, he mostly rolled around and died. MOSTLY.) I figured I'd try the online in II. I had a surprisingly fun time with it. I loved helping people out, there's nothing quite like a triangle of three sunbros repeatedly praising the sun after a defeated boss.
However, in Dark Souls 2, it's a lot harder to team up with specific people, unless you're pretty much at exactly the same point in the game. The game takes into account not just level, but total souls acquired. Some people grind for souls and buy things (or die and lose those souls), so two people at the same level can have wildly varying soul counts, and be unable to summon each other. If you're just seeking help from randoms, this really doesn't impact you.
I also agree that the difficulty of Dark Souls is overhyped. Yes, you might die a lot in the beginning, especially if it's your first foray into this game, but once you get into the groove of things, the deaths are fewer and farther between.