The part of a computer used to store programs and data is memory. Memory is a very important part of the computer, it can be regarded as the "brain" of the computer, used to store a variety of data and programs. According to the different types and functions of memory, it can be divided into two types: memory and external memory. Memory is the main storage device in the computer, which is used to store running programs and temporary data, and its reading speed is very fast. External memory, on the other hand, is the auxiliary storage device of the computer, such as hard disk, CD-ROM and USB flash drive, which has a larger storage capacity than the memory, but has a slower reading speed. The size of memory capacity is usually expressed in bytes, while the access speed is expressed in bytes per second or megabytes per second.

In addition to RAM and external memory, there are some other types of memory, such as cache memory, virtual memory, and so on. Cache memory is a type of high-speed memory that is used to temporarily store frequently used data in the main memory to increase the speed of computer operation. Virtual memory, on the other hand, is a technology that uses hard disk space as memory, which can store a portion of data and programs on the hard disk to meet the needs of running programs when memory is insufficient.

As computer technology continues to evolve, so does the capacity and read speed of memory. Now, we can easily have hundreds of gigabytes of hard disk and several gigabytes of memory, which makes the running speed and storage capacity of the computer has been greatly improved. At the same time, with the rise of cloud computing and big data technology, the demand for memory is also increasing, which will further promote the development of memory technology and bring more efficient and convenient storage solutions for computer applications.