Like many people you wonder what a Custom ROM is and especially what it can be used for. Small remedial course for beginners who feel a little overwhelmed by all these technical terms..
What is a Custom ROM?
Firmware, Root, Recovery, Fastboot, the world of Android is full of Anglicism and Anglo-Saxon expressions. It is a fact that is hardly disputable. Your entourage or your friends may have already told you about ROM Custom.
First of all it is worth considering the meaning of this technical term. The acronym ROM is made up of the initials of the words Read Only Memory . It designates a non-volatile memory system also called read-only memory. The data recorded on this type of medium can be read several times by users but will not be erased once the device is switched off (no longer supplied with electricity)..
With the arrival of smartphones, the term and use of ROMs has changed slightly. Unlike the first versions of read-only memories whose contents were fixed ad vitam aeternam during their manufacture, the ROM on a telephone can be modified.
Is all this still unclear? To put it simply, ROM is the physical medium on which is stored the Android system equipping your smartphone or tablet. The word has gradually democratized so that today ROM is used to designate the operating system of the mobile..
Should you install a Custom ROM on your phone?
Today there are two types of ROM. On the one hand the official versions developed by the manufacturers of smartphones and on the other the versions called Custom (personalized) developed by enthusiasts of Android with a solid technical background. 
Among the best known are CyanogenMod, OmniROM or LineageOS.
Why install a Custom ROM on your phone? Most of the users who have chosen to install these alternative systems have done so in order to be able to take advantage of the latest versions of Android. Indeed, most manufacturers offer software support limited to smartphones that are less than two years old.
Thanks to ROM Custom, it is thus possible to take advantage of the latest Android features even if the manufacturer no longer offers updates. These alternative systems also offer the advantage of being able to delete all the applications preinstalled by default on the phones (weather, widget, music player). As you know, these apps don't do much. They generally take up a lot of space in the storage memory and use the battery of our devices.
The vast majority of Custom ROMs prove to be lighter than the systems originally installed by the manufacturers. As a result, the phones perform better. Faster, faster, they are more pleasant to use.
Likewise a lighter system requires less processor and RAM memory. This allows users to offer a few tens of minutes or even several hours of additional use. Custom ROMs improve the autonomy of tablets and smartphones.
How to install a Custom ROM?
Installing a Custom ROM requires some technical knowledge. Please note this operation can quickly turn into a Stations of the Cross. If you are a neophyte you will quickly realize that despite your talent, the world of alternative systems is not within your reach.
In the event of failure, neither the author of this article nor getFastAnswer can be held responsible for damage caused to your device. Note that the installation of a Custom ROM can be done even if your smartphone is not rooted. However it is recommended to have root rights. Indeed a very large number of ROM Custom offer options requiring root rights.