A question about weed consumption (serious)

[Dystopia]

I'm not personally a weed consumer, even tough I've tried it a few times. I'm curious about something:

From reading in international forums, talking to friends who've traveled and observing real life experiences and interactions, it seems Americans (and maybe Canadians and Australians too, but I don't know) smoke just weed, or "pure weed" like we call it in Europe, whereas Europeans mix it with tobacco. Why does it work like this and why do some people prefer one method over the other?

As far as I'm concerned, most of my friends who smoke prefer hashish, not actual weed, because it is cheaper, however many say that it will not burn correctly if it's not mixed with tobacco, so they mix it with rolling tobacco (like Amber Leaf) - Plus, people usually tell me that smoking a joint with "just weed" is very strong even for experienced users. Others tell me that the amount of weed needed to get several people high doesn't justify putting weed in a whole joint, so they mix with tobacco. I'm kinda noob on this, so could someone explain it to me? And how does real weed distinguish itself from hash? Most of my friends who smoke, have these solidified brown bars, that you remove a piece, burn it with a lighter, mix with tobacco and roll it in a king size paper with a handmade filter tip (it can be made out of cardboard, paper, whatever, but people don't use actual filtertips for rolling tobacco). 

Thanks for the replies

From my own experience I'd say there's not that much difference between hash and real weed except maybe you get a bit more stoned with real weed. 
But then I also found that eating hash got me even more stoned than smoking either real weed or smoking hash.
Just thinking back to smoking weed gets me depressed about all that money I wasted smoking it and how crap of a drug it is.

So you just eat it? I don't know, but my friends say there's a notable difference between hash and weed - It also depends to whom you buy the weed and hash, and how much you trust that person. From my limited experience, I felt better when smoking actual weed, and about half the times I smoked hashish I felt ill and had to vomit, my mouth was also super dry. I also tried one of those legal synthetic drugs sold in some countries' stores labeled as "house items", that are not really house items but drugs made in labs meant to simulate the effects of real drugs like cannabis, hash, etc - It was a terrible experience and I was passed out for 8 minutes. Can't recommend.