Computer memory is a generic term for all of the different types of data storage technology that a computer may use, including RAM, ROM, and Flash memory. Some types of computer memory are designed to be very fast, meaning that the central processing unit (CPU) can access data stored there very quickly. Other types are designed to be very low cost, so that large amounts of data can be stored there economically. Another way that computer memory can vary is that some types are non-volatile , which means they can store data on a long term basis even when there is no power. And some types are volatile , which are often faster, but which lose all the data stored on them as soon as the power is switched off. A computer system is built using a combination of these types of computer memory, and the exact configuration can be optimized to produce the maximum data processing speed or the minimum cost, or some compromise between the two. Types of Computer Memory: Primary and Seconda