Computer memory is used to store data and instructions and can store both input and output. There are two main types of computer memory: primary and secondary. Primary memory, also called main memory, is semiconductor-based and volatile, storing data and programs temporarily while the computer is on. It includes RAM and ROM. RAM is used for running programs and can be static RAM (SRAM) or dynamic RAM (DRAM). ROM is non-volatile and stores the basic instructions for starting the computer. Secondary memory is non-volatile storage like hard disks, floppy disks, CDs, DVDs, flash drives, and SD cards, which can store large amounts of data and is accessed by transferring data to primary memory.
2. COMPUTER MEMORY
Computer memory is just like the human brain. It is used to store
data/information and instructions. It is a data storage unit or a data storage
device where data is to be processed and instructions required for processing are
stored. It can store both the input and output can be stored here.
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4. PRIMARYMEMORY
It is also known as the main memory of the computer system. It is used to
store data and programs or instructions during computer operations. It
uses semiconductor technology and hence is commonly called
semiconductor memory.
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6. RAM(RANDOMACCESSMEMORY)
It is a volatile memory. Volatile memory stores information based on the power supply.
If the power supply fails/ interrupted/stopped, all the data & information on this
memory will be lost. RAM is used for booting up or start the computer. It temporarily
stores programs/ data which has to be executed by the processor.
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8. SRAM (STATICRAM)
It uses transistors and the circuits of this memory are capable of retaining
their state as long as the power is applied. This memory consists of the
number of flip flops with each flip flop storing 1 bit. It has less access time
and hence, it is faster.
9. DRAM(DYNAMICRAM)
It uses capacitors and transistors and stores the data as a charge on the
capacitors. They contain thousands of memory cells. It needs refreshing of
charge on capacitor after a few milliseconds. This memory is slower than S RAM.
10. ROM(READONLYMEMORY)
It is a non-volatile memory. Non-volatile memory stores information even when there is a power supply failed/
interrupted/stopped. ROM is used to store information that is used to operate the system. As its name refers
to read-only memory, we can only read the programs and data that is stored on it. It contains some electronic
fuses that can be programmed for a piece of specific information. The information stored in the ROM in
binary format. It is also known as permanent memory.
11. SECONDRYMEMORY
It is also known as auxiliary memory and backup memory. It is a non-volatile memory and used to
store a large amount of data or information. The data or information stored in secondary memory is
permanent, and it is slower than primary memory. A CPU cannot access secondary memory directly.
The data/information from the auxiliary memory is first transferred to the main memory, and then
the CPU can access it.
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13. FLOPPYDISK
A floppy disk consists of a magnetic disc in a square plastic case. It is used to store data and to
transfer data from one device to another device. Floppy disks are available in two sizes (a) Size: 3.5
inches, the Storage capacity of 1.44 MB (b) Size: 5.25 inches, the Storage capacity of 1.2 MB. To use a
floppy disk, our computer needs to have a floppy disk drive. This storage device becomes obsolete
now and has been replaced by CDs, DVDs, and flash drives.
14. HARDDISK
A hard disk is a part of a unit called a hard disk drive. It is used to storing a large amount of data. Hard disks
or hard disk drives come in different storage capacities.(like 256 GB, 500 GB, 1 TB, and 2 TB, etc.). It is created
using the collection of discs known as platters. The platters are placed one below the other. They are coated
with magnetic material. Each platter consists of a number of invisible circles and each circle having the same
centre called tracks. Hard disk is of two types (i) Internal hard disk (ii) External hard disk.
15. FLASHDRIVE
A flash drive or pen drive comes in various storage capacities, such as 1 GB, 2 GB, 4
GB, 8 GB, 16 GB, 32 GB, 64 GB, up to 1 TB. A flash drive is used to transfer and store
data. To use a flash drive, we need to plug it into a USB port on a computer. As a flash
drive is easy to use and compact in size, Nowadays it is very popular.
16. SDCARD
It is known as a Secure Digital Card. It is generally used in portable devices like mobile phones, cameras, etc.,
to store data. It is available in different sizes like 1 GB, 2 GB, 4 GB, 8 GB, 16 GB, 32 GB, 64 GB, etc. To view the
data stored in the SD card you can remove them from the device and insert them into a computer with help of
a card reader. The data stores in the SD card is stored in memory chips(present in the SD Card) and it does
not contain any moving parts like the hard disk.
17. COMPACTDISC
A Compact Disc (CD) is a commonly used secondary storage device. It contains tracks and sectors on
its surface. Its shape is circular and is made up of polycarbonate plastic. The storage capacity of CD
is up to 700 MB of data. A CD may also be called a CD-ROM (Compact Disc Read-Only Memory), in
this computers can read the data present in a CD-ROM, but cannot write new data onto it. For a
CD-ROM, we require a CD-ROM.
