What are the types of memory? There are three types of internal memory

1. Classified by storage medium.

Semiconductor memory: A memory composed of semiconductor devices.

Magnetic surface memory: A memory made of magnetic materials.

2. Classification according to storage mode.

RAM: The contents of any memory cell can be accessed randomly, regardless of the time of access and the physical location of the cell.

Sequential memory: It can only be accessed in a certain order, and the access time is related to the physical location of the storage cell.

3. Classified according to the read and write function of the memory.

Read-only memory (ROM): Semiconductor memory that is fixed and can only be read out but not written.

Random read-write memory (RAM): Semiconductor memory that can be read and written to as well as both.

4. Classification according to the storability of information.

Non-permanent memory: Memory that disappears when the power is off.

Permanent memory memory: A memory that can still hold information even after a power failure.

5. Classification according to the role in the computer system.

Main memory (memory): Used to store active programs and data, with high speed, small capacity, and high price per bit.

Secondary memory (external memory): It is mainly used to store programs and data that are currently inactive, and it is slow, large, and has a low price per bit.

Buffer memory: It mainly acts as a buffer for two parts with different working speeds.

According to the working principle of memory, it can be divided into three categories: read-only memory, random memory, and cache memory.

1. Read-only memory.

At the time of manufacture, information (data or programs) is stored and stored permanently. This information can only be read out, generally not written, and this data will not be lost even if the machine has a power outage.

2. Random access.

RAM means that data can be read or written from it. When the power of the machine is turned off, the data stored in it is lost.

3. High-speed buffer memory.

When the CPU writes or reads data to memory, that data is stored in cache memory.

According to how memory works, it can be divided into two categories: read-only memory and random memory.

1. Read-only memory (English: read-only memory, abbreviation: ROM).

The data stored in the ROM is generally written in advance before loading the whole machine, and can only be read out during the working process of the whole machine, unlike random access memory, which can be quickly and easily rewritten. The data stored in the ROM is stable, and the data stored in the ROM will not change after power failure; Its structure is relatively simple and easy to read, so it is often used to store various fixed programs and data.

2. Random Access Memory (RAM), also known as "RAM", is the internal memory that directly exchanges data with the CPU, also known as the main memory (memory). It can be read and written at any time, and it is fast, often as a temporary data storage medium for operating systems or other running programs.

Storage that the contents of a storage cell can be removed or deposited as needed, and the speed of access is independent of the location of the storage cell. This type of memory loses its contents when the power is off, so it is mainly used to store programs that are used for a short period of time. According to the working principle of the memory cell, random access memory is further divided into static random access memory (English:

Static RAM, SRAM) and Dynamic RAM (DRAM).