A locksmith is a professional with a unique set of skills. You won't need one often, at least not if everything is ideal. However, you'll be glad to have access to locksmith services in any of these five situations.
The classic image of a locksmith is someone who shows up to save the day whenever you've lost access to a locked building or vehicle. If you broke your key off in the lock to your front door, for example, that's a good time to ask for locksmith services.