Neither. They both serve their purpose. Typically I recommend new users to start with machines because they take care of most of the form for you. Machines are also good to concentrate the power to a specific muscle. An example of what I mean is with the chest press. If you use a barbell to do your chest press, you’re using a lot of your stabilizer muscles, biceps and triceps to keep the bar up and straight. If any of these muscles are weaker than your chest, then you will max out before your chest gets the full benefit. The positive side to using barbells and dumbells is that they build up the stabilizer muscles that machines miss. Ultimately, you work more muscles when you use free weights, and you work individual muscles harder when you use machines. I recommend that once you get your joints strong enough and are working out regularly, that you use a combination of both machines and free weights to get a complete work out.