Assuming you are referring to remote starters for vehicles:
Most dealerships can install a remote starter in your vehicle. However, it is best to check with your specific dealership beforehand to see if they offer this service and what their rates may be. Some dealerships may outsource the installation of remote starters to a third party, so it is important to ask about this as well.
A remote starter allows you to start your car from a distance without having to be physically present in the vehicle. This can be helpful in cold weather when you want your car to warm up before getting in it, or if you want the air conditioning on before getting into a hot car. It can also be helpful if you have an alarm system that arm and disarms itself when you lock and unlock the doors - with a remote starter, you can disarm the alarm before even entering the vehicle, which can help prevent any unwanted attention or potential break-ins.
Installing a remote starter is not a difficult process, but it does require some basic knowledge of cars and how they work. If you are not comfortable doing it yourself, then taking your car to a dealership or third party installer is definitely the way to go.