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Types of memory in computer
In this article we will discuss what is memory and what are the types of memory in computer in detail with real life examples. After reading this article you will not have any doubt on memory and types of memory in computer. Lets understand the topic.
Memory
Memory is that part of a computer which stores data and instructions whether for a short period or long period. These are the storage space in a computer which holds data and instructions temporarily or permanently. Just like in case of human being, we store some data for a short period of time and some for longer duration. Now we will try to understand which type of memory stores data for short period and which stores for longer duration.
So lets know what are the types of memory in computer in detail with examples.
Types of memory in computer
There are mainly two types of memory in computer
- Primary memory
- Secondary memory
Primary memory
- Primary memory is the main memory of a computer.
- It is also called the internal memory of a computer.
- It stores those data and instructions which are currently being processed by the CPU.
- It is the temporary memory of a computer which retains data and instructions only for a short period of time.
- It is volatile in nature as the contents of this memory gets erased when computer is switched off or the power supply to a computer is stopped.
- It is smaller in size than secondary memory. that is why it can store a small amount of data in comparison to secondary memory.
- It has fast access time i.e. CPU can access data faster from primary memory than secondary memory.
- It is made from semi conductor material that is why it is more expensive than secondary memory.
- A computer can not do any work without primary memory.
Types of primary memory in computer
Now let’s see what are the various types of primary memory in a computer.
There are two types of primary memory such as RAM and ROM
RAM
- RAM stands for Random Access Memory.
- It is made from semiconductor material that is why it is costlier than secondary memory.
- It stores data and instructions for a short period of time.
- It is called the temporary or volatile memory as the contents stored gets erased as soon as the computer is switched off or the power supply to the computer is cut.
- It has fast access time than Secondary memory.
- It is smaller in size than secondary memory.
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Types of RAM in computer
There are two types of RAM in computer such as
- SRAM
- DRAM
SRAM
- SRAM stands for Static Random Access Memory.
- The data stored in SRAM does not get erased as long as the computer is switched on.
- The main memory of a computer i.e. RAM is the SRAM.
- SRAM does not need to be refreshed periodically to store data in it unlike DRAM.
- SRAM is a fast memory.
- SRAM is costlier than DRAM.
- It stores a small amount of data
DRAM
- DRAM stands for Dynamic Random Access Memory.
- DRAM is used as the cache memory of a computer.
- DRAM needs to be refreshed periodically to store data for longer period of time.
- The storage capacity of DRAM is kore than SRAM.
- DRAM is cheaper than SRAM.
- DRAM is slower than SRAM
ROM
- ROM stands for Read Only Memory.
- This memory can only be read, the programs stored in it cannot be changed.
- This memory stores some fixed programs which helps to operate a computer system such as BIOS (Basic Input Output System)
- ROM is non volatile in nature i.e. the contents stored it does not get erased even if the computer is switched off or the power supply is cut.
- It stores a small amount of data than RAM.
- It is slower than RAM.
- It is cheaper than RAM.
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Types of ROM in computer
There are three types of ROM in computer such as
- PROM
- EPROM
- EEPROM
PROM
- PROM stands for Programmable Read Only Memory.
- It is a one time programmable chip. The programs stored in it can reprogrammed only once after manufacturing process.
- The writing process in PROM is performed electrically with a special equipment.
- PROM is more flexible and convenient to use than ROM.
- PROM is also non volatile or permament like ROM.
- It is costlier than ROM but cheaper than EPROM.
- PROM is an older version of ROM.
- It is completely covered by plastic.
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EPROM
- EPROM stands for Erasable Programmable Read Only Memory.
- The programs stored in EPROM can be reprogrammed by exposing the chip to ultra violet ray.
- EPROM is costlier than PROM.
- It is an improved version of ROM.
- It is covered by Transparent Quartz Window.
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EEPROM
- EEPROM stands for Electrically Erasable Programmable Read Only Memory.
- EEPROM can be reprogrammed with the help of electric charge.
- EEPROM is costlier than EPROM.
- It is a modern version of ROM.
- It is covered by an opaque plastic box.
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There is another type of primary memory available in a computer such as Cache memory
Cache memory
- Cache memory is a small sized very fast memory placed between RAM and CPU of a computer.
- It stores data and instructions which are frequently needed by CPU.
- It stores a small amount of data.
- It stores data for a short period of time.
- It helps in improving the overall performance of a computer.
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Secondary memory
- Secondary memory is the permanent memory of a computer.
- It is also called external or auxilary memory of a computer.
- It is non volatile in nature i.e. the contents stored in secondary does not get erased even if the computer is switched off or the power supply is cut.
- It has high storage capacity than primary memory.
- There are various storage media where secondary memory exists such as Magnetic media and Optical Media
Examples of Secondary memory
There are two types disks having secondary memory such as
- Magnetic Disk
- Optical Disk
Examples of Magnetic disks are
- Hard Disk
- Floppy Disk
Examples of Optical Disks are
- CD (Compact Disk)
- DVD (Digital Versatile Disk)
- Blue ray Disk
- Pen Drive/ Flash Drive
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Real life examples
Now lets understand primary memory (RAM) and secondary memory with the help of real life examples
we read different books. The books are kept safely somewhere in our house such as Book shelf or almirah. Now, to read a particular book we bring the book from bookshelf or almirah and keep it on the table where we regularly study and after completing the reading we again keep the book in bookshelf or where the books are generally kept.
Now in this case our study table is RAM where we work on data, file. Files are not stored permanently here, it remains as long as we are working on it. To work on file, we will have to bring it from secondary memory like we bring book from Bookshelf or almirah to study in the above example and after we finish working on a file when we save it, it automatically gets saved in our secondary memory.
In the example if the size of the study table is large then we can keep many books. In the same way if the size of RAM is large, computer can work on multiple files without degrading its performance.
Diagram on the types of memory in computer
Now let’s understand the types of memory in computer with the help of the diagram given below
Conclusion
friends, after reading this article on types of memory in computer you must have a clear concept on it. If you have still doubts, you can ask me in the comment section or you can give me feedback below.
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Welcome to my site. I am the founder of the blog elearnersmentor.com. I have been in teaching profession since 2004. Presently I am working as a vocational subject teacher(IT) in a reputed govt. higher secondary school. Read more