Primary storage is a crucial component of a computer system, as it refers to the memory where data and programs are stored for quick access by the CPU. There are several synonyms for primary storage, including main memory, internal memory, and primary memory. Main memory refers to the storage space that is directly accessible by the CPU and is divided into volatile and non-volatile memory. Internal memory, on the other hand, refers to the storage space that is directly connected to the computer's motherboard, such as RAM. Finally, primary memory, which can refer to the same storage space, also includes the idea that this memory is the primary place where the CPU accesses data and programs.