Memory is the internal storage areas in the computer. The term memory identifies data storage that comes in the form of chips. Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM. A computer that has 32 megabytes of memory can hold about 32 million bytes (or characters) of information.

EDO, short for Extended Data Output, is a type of DRAM that is faster than conventional DRAM. Unlike conventional DRAM, which can only access one block of data at a time, EDO RAM can start fetching the next block of memory at the same time that it sends the previous block to the CPU.

SDRAM, short for Synchronous DRAM, is a new type of memory that can run at much higher clock speeds than conventional memory. SDRAM actually synchronizes itself with the processor's bus and is capable of running at 100MHz or 133MHz, more than two times faster than conventional EDO DRAM.

DIMM, short for dual in-line memory module, is a small circuit board that holds memory chips. A SIMM, short for single in-line memory module, has a 32-bit path to the memory chips whereas a DIMM has 64-bit path. Because the Intel Celeron and Pentium processors require a 64-bit path to memory, you need to install SIMMs two at a time. With DIMMs, you can install memory one DIMM at a time.

ECC is short for Error-Correcting Code memory. This type of memory has special circuitry that tests the accuracy of data as it passes in and out of memory. Error correction can be done in either software or hardware, but if the errors must be corrected as the data is being read from the disk, the implementation must take place in the hardware. RAIDs (Redundant Arrays of Inexpensive Devices) use error correcting systems to create fault-tolerance.