What is RAM?
Random Access Memory (RAM) is used to store the programs and data being used by the CPU of your computer in real-time. RAM is like a temporary memory storage where your computer stores data it needs to retrieve quickly. RAM is a hardware element where only the data which is being currently used is stored. It is a volatile type of memory. Types of RAM:
- Static RAM or SRAM.
- Dynamic RAM or DRAM.
When you open a program such as Microsoft Excel, your computer loads the application into its RAM. If you open any document you already have saved on your computer, the operating system locates the file in long-term storage and copies the information onto its RAM. Once the data is in your RAM, you get near-instant performance because RAM is lightning fast.
What is ROM?
ROM stands for Read Only Memory. It is called read only memory because we can only read the programs and data stored on it but cannot write on it. It is restricted to reading words that are permanently stored within the memory.
Data stored in ROM is retained even after the computer is turned off. ROM is non-volatile. Types of ROM: Programmable ROM, Erasable Programmable ROM(EPROM), Electrically Erasable Programmable ROM(EEPROM), Mask ROM.
A simple example of ROM would be the cartridge used in video game consoles that allows the system to run many games. The data which is stored permanently on personal computers and other electronic devices such as smartphones, tablets, TV, AC, etc. is also an example of ROM.
What is EEPROM?
EEPROM (Electrically Erasable Programmable Read Only Memory) is a special type of ROM that can be erased and reprogrammed repeatedly through a normal electrical voltage. It is a non-volatile type of memory which uses electron field emission to electrically erase data.
Difference Between RAM, ROM and EEPROM
Data stored in RAM can be retrieved and altered. Data stored in ROM can only be read. Whereas data stored in EEPROM can be read, erased as well as reprogrammed.
Comparison Between RAM, ROM and EEPROM
| Parameter of Comparison | RAM | ROM | EEPROM |
| Full form | Random Access Memory | Read Only Memory | Electrically Erasable Read Only Memory |
| Definition | RAM is used to store the programs and data being used by the CPU in real-time. | Data stored in ROM is retained even after the computer is switched off. | EEPROM is a special type of ROM that can be erased and reprogrammed repeatedly through a normal electrical voltage. |
| Developer | Developed by Robert Dennard in 1968. | Developed in 1967 by Dawon Kahng and Simon Sze of Bell Labs. | Developed by George Perlegos in 1978. |
| Data retention | RAM is a volatile memory which could store data as long as the power is being supplied. | ROM is a non-volatile memory which can retain the data even when power is turned off. | EEPROM is a non-volatile memory which could retain the data even when power is turned off. |
| Working type | Data stored in RAM can be retrieved as well as altered. | Data stored in ROM can only be read. | Data stored in EEPROM can be retrieved and altered. |
| Price | It is not costly. | It is not costly. | It is more expensive than ROM. |
| Use | Used to store the data that has to be processed by CPU temporarily. | It stores the data and instructions required to be permanently stored in the computer. | EEPROMs are used in many applications such as telecom, consumer, automotive and industrial applications. |