Free weights and machines both have their pros and cons, the key is to figure out which one is right for you. When you enter most gyms today, the first things you usually see are weight stations set up to work each muscle in your body. All you have to do is sit down, and let the machine guide your body through series of particular movements. While the machine provides all the resistance, the only thing you need to do is push or pull. Free Weights on the other hand, will permit you to move your body through a variety of planes and natural motions. This allows you to mimic movements you do in real life such as squatting, lifting, and rotating the body in circular motions. The majority of the time free weights are usually in back of the gym, where most of the experienced lifters are.
Machines are great for beginners because they do not have much of an intimidation factor. You can easily select a weight that is appropriate for you because the machines control the movements. All you have to do is just follow the machine's range of motion to guarantee that you hit your target muscle. Since beginners are not well educated on weight training and the proper form, the machines can offer easy guidance, which can ultimately help prevent injuries. Whereas Free Weights are good for intermediate and advance lifters because they know how lift correctly and use proper form. Free weights are very intimidating and require skill and coordination, so you may need some instruction for using them for the first time. Free weights are more susceptible to injuries, because it is very easy to tear a muscle or move a body part out of alignment, which could cause a serious problem.
References: bodybuilding.com (nd), Retrieved from http://www.fourm.bodybuilding.com