Instead of lots of keys for lots of locks:
you now only have one key for everything.
You can use your key to lock the front door, the garden gate, the letterbox,
the garage door, the basement access, the tool shed – or to put it in a nutshell:
everything that is to be locked on, around and in the house!
If your house should not only be used privately, but also as a business,
then you can grant additional or restricted authorizations by using a locking system.