Secondary memory is a type of computer memory that is not directly accessed by a computer’s central processing unit (CPU) and is generally available as non-volatile memory. One of the most common forms of this memory is a computer’s hard drive, which is used to store the operating system (OS) and other programs. Other forms of secondary memory include disk drives for compact discs (CDs) or digital versatile discs (DVDs), as well as removable flash memory. In contrast to this, primary memory is computer memory that is directly accessed by the CPU, usually volatile memory, and tertiary memory refers to systems external to a computer that can be accessed directly through various media.
USB devices use secondary memory.
There are several different types of memory used by computer systems, with secondary memory being one of the most common and important. This type of memory is generally recognized by the way a computer system uses it and the way data is stored in it. The main characteristic of this type of memory is that it is not accessed directly from the CPU, but through a connection that allows the use of the CPU. Generally, this type of memory is also non-volatile, meaning it retains data even without a power supply.
A computer’s hard drive qualifies as secondary memory.
One of the most common types of secondary memory is a computer’s hard drive. The CPU accesses this drive through one of several different indirect methods, and the data remains on the drive even without a power supply. Other disk drives, such as those used with CDs and DVDs, are also types of secondary memory used for other purposes. Easily removable memory types, such as flash drives, are also secondary memory and use interfaces such as a universal serial bus (USB) port that is accessed by the CPU.
In addition to secondary memory, many computer systems also use primary memory, tertiary memory, and offline storage. Primary memory is memory in a computer that is directly accessed by the CPU, that is, random access memory (RAM) and memory used to store the basic input/output system (BIOS). Tertiary memory is usually external memory that can be directly accessed by a computer through some kind of automated system, such as a bank of hard drives that can be connected to a computer through the use of a robotic armature. Offline storage is memory that can be used and accessed remotely, such as servers that can be used over an Internet connection for data storage or backup.
