Traditional residential framing
Wood stud framing, also known as stick framing, is the most used method of building both interior and exterior walls. The most common studs and top and bottom plates are made out of pine. Using pine keeps the price down since its easy to work and grows very quickly. It's a very renewable resource.
In the old days, when carpenters erected a house that was two stories or more, the method used was balloon framing. This means that the studs on the exterior wall went all the way up. This made for some very long stock; quite inconvenient. It was time for something a little more manageable.
The answer was a framing method called platform framing. This started to be the preferred method during the 1920's. Aptly named, the upper stories were built with normal length studs on the "platform" made by the top of the lower story. Not only were materials standardized, but construction was much easier.
Pros and cons of wood stud framing
On the pro side, wooden studs are very inexpensive, especially when bought in bulk. It's a pretty competitive market, with most stock coming from the U.S. and Canada. (Finally, something not from China!) It's also easy to work with. Since it's a soft wood, it cuts easily.
On the con side, most of it is cut to fit at the job site. This makes for a lot of scrap, which is the antithesis of building green. Luckily, some of this scrap can got to facilities that make fuel for pellet stoves. This is done when it's economically feasible.
Another problem is that many studs are warped, which makes it hard to apply drywall at times. And of course, since it's wood, it burns readily. Not a great trait in a home. But the chances for a catastrophic fire are greatly diminished with the next wall framing technology we'll talk about: metal studs.