In computing, memory refers to all the physical devices that data or information either on temporary basis for current or future use by the computer or other digital electronic devices. Computer memory components are divided into primary and secondary memory. Primary memory is part of memory components that is used for information in physical systems which are fast (i.e. RAM) while secondary memory refers physical devices for program and data storage which are normally of higher storage capacity and are normally slow to access.
In the early 1940s memory components only allowed a few bytes in their memory capacity. The first programmable computer the vacuum tube could only perform simple calculations involving 20 numbers and ten decimal digits. Later through introduction of glass filled with mercury and plugged in at each end with mercury could store a few bits of data. In the 1940s scientist came up with non-volatile memory through the development of magnetic core memory.
This magnetic core memory was the form of memory used until the invention of transistors in 1960’s.
In the memory components, volatile memory refers to that computer memory that requires power to maintain the stored information. Most of the modern volatile memory components are either Static RAM or Dynamic RAM. Static RAM retains its contents as long as power is connected to and it uses six transistors per bit. Dynamic RAM is complicated to control and interface to as it requires regular refresh cycles in order to retain its data; however DRAM uses only one capacitor and transistor per bit.
SRAM is not suitable for desktops where the DRAM dominates although it is used for their cache memories, SRAM is mainly found in small embedded systems which might need a few kilobytes. However, there are other volatile computer memory components that are expected to either replace or compete with SRAM and DRAM these include: Z-RAM, TTRAM, A-RAM and ETA RAM.
In the Random Access Memory (RAM), data is not permanently stored and it is immediately erased when the application using it is closed or in other cases such as when the power goes off. Memory components such as the RAM, which is normally in form of a chip and comes in various memory sizes can be used to increase the efficiency and speed of the computer by simply increasing the RAM, the PC can perform various tasks using the temporary memory by saving the time used to draw data back and forth from the hard disk.
There are other computer memory components known as non-volatile memories these are computer memories that retain the stored information even when not powered. Examples of these memory components include the read only memory(ROM), flash memory and most types of magnetic computer memories (e.g. hard disks, floppy disks and magnetic tapes ), optical disks and other earlier forms memory storage devices like the paper tapes and punch cards. Some of the new forms of no-volatile technologies are FeRAM, CBRAM, PRAM, SONOS and Millipede among others.
Proper management of memory components is very important for the computer memory to function properly and give desirable results, otherwise poor management will lead to slow performance and even viruses or other malicious software