What type of memory is primary and allows both data and program instructions to be read from or written to it?

The correct answer is Random Access Memory (RAM). RAM is a type of volatile memory that provides space for the computer to read and write data and program instructions actively in use. It allows for quick access to this information, which is essential for the efficient operation of applications and the operating system. The read and write capabilities mean that data stored in RAM can be modified, which is crucial for tasks such as running programs and processing data in real time.

In contrast, Read Only Memory (ROM) is non-volatile memory that is primarily used to store firmware and permanent instructions, which cannot be written to or modified under normal operation. Flash Memory, while it can be read from and written to, is primarily used for storage rather than as primary memory for running applications. Caching Memory serves a specific purpose of speeding up access to frequently used data but does not function as primary, general-purpose memory like RAM does.