Is there a difference between the two? Will lifting free weights make me gain muscles faster?
I think you're referring to selectorized weight machines. There is a huge difference between the two.
Except for the specific movement, a machine does the rest of the work for you. Allow me to explain. When doing a machine chest press your body is responsible for only the positive and negative pushing movement. When you utilize barbell or dumbbell your body is responsible for maintaining stability on all planes of movement (Keeping the bar from tipping, wobbling, going to far over your stomach, going to far back over your shoulders.)
Free weights challenge all the synergistic muscles that aren't otherwise touches when using machines.
Does this impact my development? For example, bench press using free weights vs. the machine weights, will my development be the same or less using the machine weights?