It's important to teach puppies to 'come' when they are called. This will enable you to, for example, call your puppy back if he is heading towards a dangerous situation, such as a busy road.
If your puppy comes back to you reliably, you can allow your puppy more freedom because you'll feel more confident to allow him off the leash more often (where it is safe and legal to for your puppy to be off leash).