Computer Memory is one of the most important parts of the computer. Once the computer were only used to perform the functions and display the information on the output devices such as screens and 7 segment displays etc. after the need was felt for the storage devices to keep the result/ output or the processed data for a longer time in the computer and everyone can fetch the data after many years and so on. Computer Memory and storage devices and their types.The data will persist in the memory for a longer time so long till the computer is not crashed or it is not affected by some external software programs such as virus.
Memory of the computer can be divided into 2 basic types. These are persistent and non persistent memories. Storage devices and memories are used in different contexts. The term memory is used in the context of the processed information or the information being processed. The term storage is used to define the persistent storage which can stay in the computer also after the computer is switched off.
The memory can be divided into 2 main types:
1. RAM (Random Access Memory)
2. ROM (Read Only Memory)
In RAM also called the primary memory of the computer is the place or memory location where all the processing work takes place. This is one of the fastest memories that computers have. The other fastest memories are Cache memory and Registers.
In ROM the instructions and circuits are made at the design time and it generally contains the configuration information of the computer which do not need to be changed. The ROM is coded at the time of manufacturing and it remains the same for all the times.
Categories of ROM
There are also some categories of ROM based on the erasable or programmable memories. These are
1. EROM (erasable ROM)
2. EPROM( Erasable Programmable ROM)
3. PROM (Programmable ROM)
4. EEPROM( eclectically erasable and programmable ROM)
ROM has read only information and generally it does not change. If we want to change the information the ROM has to be electrically erased using some magnetic or laser technology.