What are the Differences Between RAM & ROM? With Their Types
A computer or digital devices use memory components to store their data for several purposes. Without any memory units, a computer cannot do any task. There are two types of memory components in digital devices i.e. RAM & ROM. In this article, we will study these two memory components and describe their difference as well.
RAM (Random Access Memory)
Random Access Memory is also known as RAM is a type of memory which stores data temporarily as long as power is supplied to it. It is a volatile memory because the data is removed once the power supply is stopped. A digital device can easily read or write the data stored on RAM compared to ROM. RAM stores the data & instruction that are currently being used by the system for fast processing.
There are two types of RAM i.e. 1) DRAM 2) SRAM
1) DRAM (Dynamic RAM)
Dynamic RAM is a type of RAM, where the data is stored using a capacitor with a pair of transistors. Due to the leakage current of the capacitor, DRAM loses its data with time, which is why it needs to be recharged (refreshed) after some time. During the refresh time, the data cannot be accessed, which makes its processing slow. It is inexpensive.
2) SRAM (Static RAM)
This type of RAM stores the data using flipflops (logic gates). There is no leakage current, which is why it does not need to be refreshed. Comparatively, it is faster & expensive than DRAM.
ROM (Read-Only Memory)
ROM stands for as Read-Only Memory is a type of memory that stores data permanently. It’s a non-volatile memory that stores data even after shutting its power supply. The main reason that it is not used as a RAM is that its accessing (Read/Write) speed is very slow as compared to RAM.
ROM is also classified into few types i.e. PROM, EROM, EEROM
1) PROM (Programmable ROM)
PROM stands for programmable read-only memory. This type of memory is blank during manufacturing and is used in special-purpose devices. This type of ROM can write data using special devices. It can write data only once which why it is called OTP (one time programmable).
EPROM stands for Erasable Programmable Read-Only Memory. This type of ROM provides the benefit of erasing the data using special ultra-violet rays. Thus they can be reprogrammed using another set of data.
EEPROM stands for Electrically Erasable Programmable Read-Only Memory. This type of ROM gives the advantage of erasing the memory using electrical pulses. This enables the read/write process considerably easy and user-friendly.
Differences Between RAM & ROM
|RAM stands for Random Access Memory||ROM stands for Read-Only Memory|
|It is used for storing programs, data & instruction that are currently being used by the system||It stores the data permanently for the system startup or boot process.|
|It needs a constant flow of power to retain its stored data.||It does not depend on the power supply.|
|Read/Write speed is incredibly faster than ROM||ROM accessing speed is very slow as compared to RAM|
|RAM is comparatively expensive||Inexpensive as compared to RAM|