The chest press is by far one of the best exercises to develop upper body strength and muscle. It works the chest, front delts (shoulders) and triceps.
The most common way the chest press is done is with a barbell – aka: the bench press. Using free weights have some important benefits over a machine, the barbell usually allows a greater range of motion, and since the movement isn’t fixed, your body needs to recruit much more stabilising muscles that aren’t used as much with the machine.
But free weights isn’t the best for everyone, and the machine have some important benefits. First, the machine is usually much safer. Many people got injured by accidentally dropping the barbell on their face or chest. This can happen easily if you train near failure. Doing the bench press safely will require some learning and experience while the machine is usually very easy to start with. Therefore it is better to use the machine if you’re new in training, or if you don’t have a spotter or a power rack.
Second, for some people with shoulder injury, using free weights might cause trouble and pain, while the machine allows a much more limited range of motion which may be the better alternative.
And third, the machine is sure is much more time efficient. Loading and removing stacks of plates might take more time than the exercise itself, the machine lets you change the weight and start working in a matter of seconds.