Computer RAM

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					A computer RAM stands for Random Access Memory. RAM is a kind of data
storage device. It comes in the category of volatile memory which means
that it retains data only when there is power supply. If the power supply
is cut off then all its data in the memory is lost. They are made of
integrated circuits which acts as storage space to store the data. The
word Random, means that data can be retrived from the RAM in any order
regardless of the physical location of the data and whether or not it is
related to the previous piece of data.

Types Of RAM :

There are two types RAM. SRAM (Static RAM) and DRAM (Dynamic RAM).

SRAM or Static Random Access Memory is a type of semiconductor memory.
SRAM uses around four to six transistors for each memory cell. Each bit
is stored in a memory cell which has either of the two stable states, 0
or 1. Due to more number of transistors present in each cell, the cells
do not need to be refreshed frequently. Refreshing a cell means re-
writing data in a cell. But it is still volatile in the sense that data
is eventually lost when there is no power supply. SRAM is faster than
DRAM in accessing data.

DRAM or Dynamic Random Access Memory is a type of RAM where each memory
cell contains a pair of a transistor and a capacitor. Each memory cell
stores a bit of data in the capacitor. Since capacitors leak charge, the
data in each cell eventually fades away unless the capacitor charge is
refreshed periodically. Since the memory cells have to be refreshed
periodically it is a dynamic memory. DRAM consumes less power compared to
SRAM. And it is also less expensive than SRAM because it contains only a
pair of a transistor and a capacitor compared to six transistors in SRAM.

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