Change Key Lock

One specific to each lock the change key which cannot operate any of the others in the set and the master key which operates all the locks in the set.
Change key lock. When you want the lock to open with a different existing key say so you no longer want to use separate keys to enter the front back and side doors the lock must be disassembled and the pins. Locksmiths typically charge a fee to re key an individual lock even when you bring it to their shop. This will push the springs out of the way and serve as a partial guide for the new lock pins. Insert the new pins in the lock.
Use alternate command keys. Re keying kits are available for most lock brands but they re not interchangeable. Since most homes have multiple doors with multiple locks re keying can get expensive. Toggle the fn lock on and the keys will function as if you re holding down the fn key all the time just as the caps lock key makes your letter keys function as if you re holding down the shift key all the time.
And if you want extra added security consider electronic door locks or even smart locks. A master key operates a set of several locks. Re keying locks gives you the option of using one key for all the exterior doors. If your keyboard has an f lock key press it to toggle between the standard commands and alternate commands.
Insert the new lock key in the cylinder. When the f lock light is off alternate functions work help undo and so on. These master keyed locks are configured to operate with two or more different keys. Re keying locks prevents you from throwing away a lot of good locks that can still be fixed.
You can re key a lock like a pro at a fraction of the cost. Learn to re key a lock. The new pins should be color coded or coded numerically to match a chart showing which pin goes where in the lock. Many new lock sets allow you to adjust the latch to either distance.
The handedness of most locksets can be changed by using an included tool. This can often be toggled with an fn lock key which functions like a caps lock key. Use the f lock key. Usually there is nothing special about the key itself but rather the locks into which it will fit.