What do you know about cargo ships?

Or freighters, or whichever. I spent all day in the port in Montréal yesterday and I saw these two HUGE boats that aren’t in use right now, so we got a real good look at them, they were just docked there. I mean seriously I never saw any boat that damn humongous. I think they’re boats for transporting large cargo around, and there was all this equipment all over both, they looked like a floating factories. One guy that was there said that one of the boats had a hydrolic crank for hauling things?
I’m asking because I’m telling a friend about them but I don’t really know what kind of boats these were, and she wants to know what they looked like beyond what I’m describing. I took pics with my cell but they turned out really bad and all you can see is a bunch of metal and sun glare.
So, does anyone here know anything about cargo ships? What do my boats sound like, and where can I go online to find pictures of similar boats?