Main Memory (RAM)
Random-access memory, or RAM, is one of the most important components in the computer. Without RAM doing anything on the computer would be much, much slower.
RAM temporarily stores (remembers) everything that runs on your Computer - and I do mean everything - the operating system (eg Windows), any applications you are using such as Word, or the game you are playing, or a web browser like Chrome, or your image editing tool. Every program you run, every file you open gets loaded into RAM so it can be used.
This happens because reading data from the Hard Drive or other secondary storage is slow and you don't want to have to keep waiting for every bit of data, every instruction to be read . RAM can be read quickly, and data in RAM can be read from anywhere (in RAM) at almost the same speed, hence the name.
RAM is volatile though - this means that once it loses power, it forgets everything. That is why we need secondary, permanent storage systems like hard drives and SSDs, which don't forget everything when you turn the system off.
Explains What RAM is and Why it is needed
