The area, where the program instruction and data are retained for processing, is called memory, like a human brain, the computer also requires some space to store data and instruction for addressing their processing. Static random-access memory (SRAM):Transistors are used to store information in SRAMCapacitors are not used hence no refreshing is required. SRAM is faster as compared to DRAM. These are expensive. SRAMs are low-density devices. These are used in cache memories. Important Points Capacitors are used to store data in DRAM. To store information for a longer time, the contents of the capacitor need to be refreshed periodically. DRAM provides slow access speeds. These are cheaper. DRAMs are high-density devices. These are used in main memories. Additional InformationHard disks are drives or devices that are used to store information outside a computer. This device may or may not be attached to the computer. Flash memory is a long-life and non-volatile storage chip that is widely used in embedded systems. It can keep stored data and information even when the power is off. It can be electrically erased and reprogrammed. Flash memory was developed from EEPROM (electronically erasable programmable read-only memory).