RAM memory is a type of temporary memory where both the data of the applications that are running and the data of the operating system with which you are working are stored.
It is said that it is a temporary memory since the operating system of the device can erase it depending on the needs it has at all times, in this memory the data and instructions that the system needs to access are stored very quickly unlike the internal memory which is where they are permanently stored (until the system or the user decides to erase).
Therefore, the amount of RAM memory is a method to know how fast and fluid a mobile phone, tablet or smart watch can work, although it is not the only variable since it depends on the rest of the components.
3 GB of RAM is more than enough to perform common tasks such as surfing the internet, using a messaging application such as WhatsApp or Telegram, using GPS or playing mobile games.
It must be taken into account that the performance of the device not only depends on the RAM memory, but also on the management that the operating system makes of that memory, which can be more or less efficient. For example, Apple devices usually have less RAM than those of other brands with Android, but nevertheless they are known for their good management of system resources, resulting in very good fluidity with less RAM.