Computer memory

Computer memory is the storage space in computer where data is to be processed and instructions required for processing are stored. The term "memory", meaning "primary storage" or "main memory", is often associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based transistors, used for example as primary storage but also other purposes in computers and other digital electronic devices.

Memory plays an important role in saving and retrieving data. The performance of the computer system depends upon the size of the memory.

Memory size refers to the size of the RAM (Random Access Memory) and the mass storage - usually magnetic hard disks.

There are two main types of semiconductor memory
*Volatile/Primary memory
*Non-volatile/Secondary memory

Secondary memory or non-volatile memory is external and permanent in nature. The secondary memory is concerned with magnetic memory. Examples of non-volatile memory are flash memory (used as secondary memory) and ROM, PROM, EPROM and EEPROM memory (used for storing firmware such as BIOS).

Primary Memory is internal memory of the computer. Examples of primary/volatile memory are primary storage, which is typically dynamic random-access memory (DRAM), and fast CPU cache memory. The primary memory provides main working space to the computer.

Memory can be classified to:
· Random access memories (RAM)
· Sequentially accessible memory (SAM)
· Direct access memory (DAM)
· Contents addressable memory (CAM)
Computer memory