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How a computer RAM works

RAM (Random Access Memory) – This article explains about working of a Dynamic Random Access Memory(DRAM). Dynamic RAM works differently from Static RAM. This article will teach you the concept of working of a DRAM.

Dynamic RAM has millions of capacitors and transistors. A transistor and a capacitor together make one bit (a bit is the smallest unit of data storage, a bit can only store either of 0 or 1). In a pair of a capacitor and a transistor, capacitors stores a bit of information i.e. a 0 or a 1, while a transistor acts as a switch that let the memory chip to read or change the state of capacitor.

How a capacitor stores a bit in a RAM

A capacitor either stores a 0 or a 1

0 – when the capacitor has no charge.

1 – when the capacitor is charged.

capacitor is like a bucket that keeps on leaking. That is, the charge stored in a capacitor continues to leak and the capacitor becomes fully discharged in a fraction of second. To overcome this problem capacitor is continuously refreshed with charge when it stores a bit as 1 therefore it is called as Dynamic.

How RAM functions

Unlike the ROM, the data in the RAM can be accessed from anywhere in the RAM that is, a RAM can v accessed randomly which gives it a name Random Access Memory. The data in the RAM is stored in the capacitors in the form of bits that is 0s and 1s.

When computer is turned ON, the data from the main hard drive is copied to the RAM. This data includes the operating system and the other applications which are running or the application programs a user is using.

This provides a quick access of the required data to the CPU. But RAM is a volatile memory, as soon as the computer is powered off, RAM loses all of its data.

Click here if you want to learn what is RAM


  1. RAM helps the cpu to quickly access the data required to run the computer and the application programs.
  2. A pair of a capacitor and a transistor together make one bit and RAM has millions of capacitors and the transistors.
  3. Dynamic Random Access Memory needs to be constantly refreshed and it is done by the memory chip.
  4. Capacitor holds the charge which represent ‘1’ and uncharged capacitor represents ‘0’.
  5. Transistor acts as a switch for memory chip to read and change the state of the capacitor.
  6. RAM is a volatile memory it loses all the data when no power is supplied to it.
  7. The operating system and any program that is running on a computer is copied from main hard drive to the RAM, so that the cpu can quickly access that data.


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