It is required to refresh _________ after a certain time interval.

Dynamic random access memory (DRAM) 

• Dynamic RAM is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit.
• Unlike static RAM (SRAM), which uses flip-flops to store bits, DRAM needs to be refreshed periodically to maintain the stored information. This is because the capacitors leak charge over time, and refreshing involves rewriting the data to prevent loss.​​

Magnetic Memory

• It is the storage of data on a magnetized medium.
• Magnetic storage uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory

Optical storage

It is any storage type in which data is written and read with a laser. Typically, data is written to optical media, such as compact discs (CDs) and DVDs