There are many different types of CPU storage, and the type referred to typically depends on the context in which the term is being used. Within a computer, the central processing unit (CPU) acts as part of the brains of the computer by processing data, but other types of storage are required to actually save that data for use by complex software programs or for long-term memory. This type of CPU storage typically falls into primary, secondary, or tertiary storage types and can be internal memory within the computer or external memory outside of the computer. The term “CPU” is often used to refer to the entire computer itself, and CPU storage can also indicate desks and other types of furniture used for housing or storing a computer.
When used in reference to computer memory, there are three basic types of CPU storage: primary, secondary, and tertiary storage. Primary storage is generally memory within the computer used directly by the CPU, and commonly consists of random access memory (RAM) the computer uses to save data short term while running programs. Secondary storage refers to memory that is accessed by the CPU indirectly and is usually handled through a basic input/output system (BIOS) or the operating system (OS) on a computer. This type of memory usually consists of hard drives or media such as compact disc (CD) or digital versatile disc (DVD) read-only memory (ROM) storage.
Both primary and secondary CPU storage are usually internal memory, though secondary storage can often take the form of an external hard drive. Tertiary storage is usually external and typically consists of a system in which large devices for memory storage are systematically chosen and then physically loaded into a computer system. This is often done through the use of a robotic arm or similar device. The external CPU storage is made available for use, then physically removed again and stored in a large library once more.
Among these three types of CPU storage there are also two different basic forms of storage: volatile and non-volatile storage. Volatile memory requires power to maintain the information stored on it and is typically used for primary storage. Non-volatile memory does not require power to keep data stored on it, and is used for secondary and tertiary storage systems.
As the term “CPU” has been extended to mean the computer itself, CPU storage can also indicate furniture and similar types of physical storage for a computer. For a desktop computer, this type of storage usually takes the form of a cabinet the computer tower can fit inside of or a small shelf on which the case sits. Laptop computers often utilize storage that takes advantage of their more portable nature and can include carrying bags and briefcases.