RAM (Random Access Memory), also called internal memory, is the memory of a laptop that lets the operating system (like Windows) temporarily store the applications in information that you're currently using. After all, the processor is able to read out information from the RAM, as opposed to the hard drive or a CD-ROM. A SODIMM RAM, which is narrower than DIMM internal memory, fits in laptops. That's why SODIMM is suitable for compact devices such as a laptop, MacBook, or iMac. Expanding the internal memory is often a smart and relatively cheap upgrade to help speed up your laptop. This type of memory is sometimes also used in all-in-one computers.