Your Options for a Doorbell.
The easiest option for a doorbell system is buying a wireless system. A wireless doorbell allows you to place the door bell button and ringer unit virtually anywhere you want to put them. They just have to be within range of each other. The sets come in various ranges depending on how expensive of a model you buy. Unless the door bell chime plugs into a wall outlet, it will be running off of batteries. As will the button unit. So you’re convenience will come at the cost of changing the batteries every so often when they wear down.
Wireless units are great for apartments and rental homes, where you may not be allowed to do any potentially destructive installations or tamper with the electrical wiring.. And on the other plus side you don’t have to hire a locksmith or electrician to install a wireless door bell.
Opposite of the wireless doorbell is the classic wired doorbell design. A wired doorbell will be connected to your house’s electricity, so there will be no need for batteries. This does mean however, that you or someone you hire will have to connect the door bell button and chime unit the wiring in you home. So your walls may be subject to some invasive damage, but it can be patched up later. The distance from button to chime unit can be as long as the length of the wires you use. But most likely the wiring will already be in place just leaving you the job of swapping units.
Both types of doorbells range in types of models, from the most basic to the fancier expensive units. The basic units will have the typical Ding Dong chime, while the fancier models have melodies, music, and other such chime options.