What type of memory is characterized by being non-volatile and storing essential programs?

The correct choice is Read Only Memory (ROM) because ROM is specifically designed to be non-volatile, which means it retains its data even when the power is turned off. This characteristic makes it ideal for storing essential programs that are needed to boot up the computer and perform basic functions, such as the BIOS or firmware.

ROM typically contains the instructions and data critical for system startup and hardware initialization. Its non-volatile nature ensures that this important information is preserved and readily available when the computer is powered on. This contrasts with volatile memory types, which lose their contents when power is lost, such as Random Access Memory (RAM) and cache memory.

Overall, ROM plays a vital role in computing systems by providing the necessary permanent storage for fundamental software that must be accessed immediately upon starting the computer.