A computer has four RAM slots, each of which can hold a different amount of RAM. So, if your computer has 4 slots, you can install up to 8GB of RAM.
However, it’s important to note that not all RAM is the same size. Some brands of RAM are smaller than others, so if you have 8GB of RAM and want to install another 4GB of RAM, you’ll need to get an upgrade from your computer manufacturer.
So, should you use all four RAM slots on your computer? That depends on what you’re using your computer for. If you’re mostly using it for work or school applications that need a lot of memory, then by all means use all four slots.
However, if you’re just using your computer for browsing the internet and streaming videos, then you may not need as much memory and can save money by using one or two of the slots.