When it comes to Weight Training there are two methods that can be used and these are free weights or
machine weights. Free Weights are the use of Barbell and Dumbbells and when using these there is not a restriction of movement. So when we target a particular muscle we will always be using other muscles apart from the targeted ones to lift the weight.
The use of machines is a bit different as we use more isolation movements, which basically means that there is a restriction to the particular muscle group that any one machine is designed for, so a leg curl on a machine is going to isolate that muscle and target it with more intensity.
When using a machine because we are in a fixed movement following the machine flow and only using the muscle group in target, we are not using any other muscles to stabilize our bodies as we would with free weights. This is why a lot of people prefer free weights as they use other muscles to perform any one exercise and it is argued that it takes more effort to use Free Weights as opposed to machines.
Machines are many peoples choice, more so in our modern world than ever before as the machines are getting more and more sophisticated. There are an array of different types of machines in any well equipped gym and they all have a specific muscle group to look after, so therefore because of the space and expense of these machines it is only the wealthy that can kit out a home gym with all the different machines.
For the not so wealthy it is still possible to have a home gym using machines. On the market today there are some really great combination gyms that pack in several machine types to one unit. They are normally referred to as a Multi-Gym and they will normally include a bench press, lat pull down station, leg extensions and preacher curl set up and any other combination. There will tend to be enough different stations within a multi-gym to work all the muscle groups to give an all body workout.
When it comes to the fight between free weights and machines, there are probably a number of reasons to choose one or the other, as machines are a fixed movement they tend to have an advantage over free weights in respect that you can't really get the technique wrong, which can mean less chance of injury. Because of that then, they are probably better for the beginner, but it is really down to personal choice which is preferred as the right type to weight train with and it is worth trying both free weights and machines to get a feel for both. A combination of the two different weight training methods is probably the best way to train.
Always consult a Doctor before starting a new Exercise Program.