Most alarm systems will have different codes that you should be familiar with. For everyday use, it shouldn't be an issue, but if you are planning on changing your alarm settings or configuration, then this is something that you should know. Each security alarm system, depending on the brand, will have its own default codes for both the installer and master code, both of which are never the same and should be changed once the system is configured.
The most common codes and the difference between each are explained below:
Installer code - An installer code is a special code that gives you access to the system in order to configure certain things like adding sensors or zones, set the clock, program schedules, change delay times. The installer code is also able to change both the installer code and the master code. It is also possible to arm and disarm the system using the installer code, but it should be noted that the installer code can only disarm the system if the same installer code was used to arm the system. If a different code, like the master code or user code, for example, is used to arm the system, then the installer code won't be able to disarm the system.
Some brands will have a way for changing the installer code if the installer code isn't known. Other brands will require the system to be factory reset which will erase all known configurations (zones) and will reset the installer and master code back to the default codes. A factory reset is only recommended as a last resort as this means the entire system will need to be configured again and reprogrammed from scratch.
Master code - A master code is usually referred to as the primary code for the alarm system, and it can do everything the installer code can do except for being able to enter system programming. The master code allows access to the user menu meaning you can add, edit, and delete user codes and also change the master code itself. The master code also allows you to disarm the system regardless of what code was used to arm the system in the first place.
User code - A user code can be added using the master code. The user code can arm and disarm the system, regardless of which code was used to arm the system. If you are sharing access with family members, you can assign each of them a specific user code. The main difference between the master code and user code is that the user code, unlike the master code, does not allow you to access any user settings as well as not being able to change itself or add, edit, or delete any other user codes.
In most common households, you can have a specific user code per family member or you could also just share a single user code (like the Master code for example). This will come down to user preference.