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Projector
A projector is a display device that projects a computer screen onto a flat surface: like
whiteboard or wall. It is most commonly used for home theaters or in organisations
for official presentations.
Projector
COMPUTER MEMORY
Computer memory holds raw data before it goes for processing and after processing it contains information which can
either be sent to output devices or stored in secondary storage devices for future use. There are two types of memory
in the computer— primary memory and secondary memory.
Primary Memory
This type of memory is necessary for a computer to work. It is also called the Internal Memory. This is the actual place
where the data is stored before it is taken to ALU for processing. Primary memory is of two types: RAM and ROM.
RAM (Random Access Memory)
It is temporary in nature. The computer holds information in this memory and gets it
when needed. It remembers what you tell them and can even change to remember
new information. It is volatile in nature, which means that data will be erased when
the computer is turned off. That’s why you always save your work! RAM is considered
Random Access Memory
“random access” because any part of it can be accessed randomly for reading or writing
of the data.
ROM (Read Only Memory)
It is permanent in nature. It is non-volatile which means even after turning your computer
off, the contents of ROM will remain. The information is coded at the time of manufacturing
the computer. The computer needs this information for its basic functions.
Read Only Memory
Secondary Memory
Secondary Memory provides extra storage where the data can be stored permanently for later use. It is also known
as external memory as it can be stored anywhere. Examples of secondary memory are compact disc, hard disc, flash
drive, etc.
Hard Disk
A Hard Disk stores and provides quick access to large amounts of data on an electromagnetically
charged surface or set of surfaces. Hard disks are generally fitted inside the system unit.
However, there are external hard disks also available. A hard disk is made-up of a collection
of disks called platters stacked on a cylindrical rod. Each of which, like phonograph records,
has data recorded electromagnetically in concentric circles or “tracks” on the disk. The
capacity of a hard disk varies from a few Gigabytes to a few hundred Terabytes. Hard Disk
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