RAM is the main memory of a device, the one where the data of the programs you are currently using is temporarily stored. Its acronym stands for Random Access Memory and is a type of memory that you can find in any device, from desktop computers to mobile phones.
RAM has two characteristics that differentiate it from other types of storage. On the one hand it has enormous speed, and on the other hand the data is only stored temporarily. This means that every time you restart or shut down your computer, it is normal for the data stored in RAM to be lost.