What is memory in computer? Computer memory refers to different types of data storage technologies used by the computer. A computer system is made up of a combination of types of computer memory. It is electronic that holds a place for instruction and data that a computer needs to reach quickly. Computer memory is the collection of storage units that store binary information in bits.
Types of Memory in Computer
primary and secondary memory.
1. Primary Memory Also known as main memory in computer, it communicates directly with the CPU, Cache and Auxiliary memory. This type of computer memory keeps data and programs when the process is active to use them. When a program or the data is activated for execution, the processor loads instructions from the secondary memory into the main memory and then starts execution. It is a volatile memory due to which any unsaved data is lost when a power cut occurs. Primary memory is of two types: RAM and ROM.
1.1 RAM RAM is hardware that temporarily stores data and programs. It is the faster part of the main memory which can be directly accessed by the CPU. It reads and writes programs until the computer is switched on.
RAM is of two types: DRAM and SRAM.
DRAM full form is Dynamic Random-Access Memory. It is a type of RAM that is used for dynamic data storage. Every cell in DRAM consists of one-bit information. A cell is composed of a transistor and a capacitor. This capacitor and transistor are extremely small in size. The capacitor needs a continuous refresh to retain information since it is volatile.
SRAM full form is Static Random-Access Memory. This type of RAM stores static data in memory which remains active until there is a power supply. Same sized SRAM chip holds less data than DRAM. Unlike DRAM, it does not require a continuous refresh.
1.2 ROM Read-Only Memory (ROM) is a permanent storage type. This is a type of read-only memory that only reads the stored information, but it does not have the capability to modify or write. Since it is a non-volatile type of memory in computer, the information stays even after a power cut or when the system has been shut down. ROM is of the following five types:
MROM: It is the oldest ROM whose data is pre-configured via integrated circuit manufacture during the time of manufacturing. Due to this pre-configuration, the user cannot change the instruction stored within the MROM chip.
PROM: It is a digital ROM which only once allows writing any information or program. This is done using a special PROM programmer or burner device.
Flash ROM: This type of ROM can be programmed or written in smaller units called sector or block. It is used for transferring data between computer and digital devices.
EPROM: In this type of ROM, data can be erased as well as reprogrammed only once. It can store data for a minimum of 10-20 years. To erase and reprogram EPROM, the user needs to pass UV light for 40 minutes. Post this, the data can be recreated.
EEPROM: The full form of EEPROM is Electrically Erasable and Programmable Read Only Memory. It is an electrically erasable and programmable ROM. This allows data to be erased using a high-voltage electrical charge. After this, it can be reprogrammed up to thousands of times.
2. Secondary Memory
It is a permanent type of memory in computer that holds a large amount of data. This is an external memory that represents different storage media on which data and programs can be saved for long term. It is not directly accessible by the CPU and is available as external devices such as CDs, DVDs and USBs. They are cheaper than primary memory but slower than primary memory.
Hard disk: It is a type of permanent computer memory that stores programs, files and data. It is stored on the motherboard of the computer that does not lose data even when there is a power outage or when the system has been switched off.
Compact Disc (CD): It is an optical disk storage device that stores different types of data, such as audio, video, files, and other information. CD uses light to read and write data from CDs.
Pen Drive: This portable device is a type of secondary memory in computer that is used for permanently storing data.