Changing locks entails removing all of the existing locks (lock, knob/lever, latch, and strike) and replacing them with a completely new lock. Re-keying a lock is the process of removing the existing lock cylinder (while leaving the rest of the lock in place) and changing it so that your existing key no longer works and a new key does. It’s more common than not that you just want your locks re-keyed. If you have an old lock that you don’t want to replace, or if you have lost your keys and need to get a new set, re-keying is a great option. A security system is also recommended if you want to ensure that only you have access to your property – for example, if you own a rental property and want to ensure that only your tenants have access to the property. Re-keying is significantly less expensive than replacing locks, and it usually takes less time as well.