Secondary Memory Definition Secondary memory refers to storage devices, such as hard drives and solid state drives. It may also refer to removable storage media, such as USB flash drives, CDs, and DVDs. Unlike primary memory, secondary memory is not accessed directly by the CPU. Instead, data accessed from secondary memory is first loaded into RAM and is then sent to the processor. The RAM plays an important intermediate role, since it provides much faster data access speeds than secondary memo...

Primary Memory Definition Primary memory is computer memory that is accessed directly by the CPU. This includes several types of memory, such as the processor cache and system ROM. However, in most cases, primary memory refers to system RAM. RAM, or random access memory, consists of one or more memory modules that temporarily store data while a computer is running. RAM is volatile memory, meaning it is erased when the power is turned off. Therefore, each time you start up your computer, the ope...

ROM Definition Stands for "Read-Only Memory." Please do not confuse this term with RAM or a hard drive, as many people already do. ROM is memory containing hardwired instructions that the computer uses when it boots up, before the system software loads. In PCs, the instructions are read from a small program in the ROM, called the BIOS (Basic Input/Output System).

RDRAM Definition Stands for "Rambus Dynamic Random Access Memory." It is a type of RAM made by Rambus (big surprise) and is the fastest type of computer memory available. Typical SDRAM can transfer data at speeds up to 133 MHz, while standard RDRAM can crank it up over 1 GHz. Though some motherboards can use RDRAM as system memory, it is so fast, most boards cannot fully benefit from the speed. Because of this, RDRAM is typically used for video memory on graphics acclerator cards, for cache memo...

SDRAM Definition Stands for "Synchronous Dynamic Random Access Memory." Yeah, it's a mouthful, but if you memorize it, you can really impress your friends. SDRAM is an improvement to standard DRAM because it retrieves data alternately between two sets of memory. This eliminates the delay caused when one bank of memory addresses is shut down while another is prepared for reading. It is called "Synchronous" DRAM because the memory is synchronized with the clock speed that the computer's CPU bus s...

DDR Definition Stands for "Double Data Rate." It is an advanced version of SDRAM, a type of computer memory. DDR-SDRAM, sometimes called "SDRAM II," can transfer data twice as fast as regular SDRAM chips. This is because DDR memory can send and receive signals twice per clock cycle. The efficient operation of DDR-SDRAM makes the memory great for notebook computers since it uses up less power.

DDR4 Definition Stands for "Double Data Rate 4." DDR4 is the fourth generation of DDR RAM, a type of memory commonly used in desktop and laptop computers. It was introduced in 2014, though it did not gain widespread adoption until 2016. DDR4 is designed to replace DDR3, the previous DDR standard. Advantages include faster data transfer rates and larger capacities, thanks to greater memory density and more memory banks (16 rather than 8). DDR4 also operates at a lower voltage (1.2V compared to 1...

Desktop Computer Definition A desktop computer (or desktop PC) is a computer that is designed to stay in a single location. It may be a tower (also known as a system unit) or an all-in-one machine, such as an iMac. Unlike laptops and other portable devices, desktop computers cannot be powered from an internal battery and therefore must remain connected to a wall outlet. In the early age of computers, desktop computers were the only personal computers available. Since laptops and tablets did not...