What are the physical types of memory?

Physical types of memory include primary memory (or volatile memory), such as RAM (Random Access Memory), which temporarily stores data for quick access by the CPU, and secondary memory (or non-volatile memory), like hard drives and SSDs (Solid State Drives), which provide long-term data storage. Additionally, there are cache memory, which is a smaller, faster type of volatile memory located close to the CPU for frequently accessed data, and flash memory, used in USB drives and memory cards, that retains data without power. Each type serves distinct purposes in a computer system's architecture.