What is memory? What are the essential differences between internal memory and external memory?

Memory is a memory device used to save programs and data, as well as intermediate results and final results of operations. The difference between internal memory and external memory: 1. The memory is a temporary storage area when executing the program, and all data will be lost after a power failure; the external memory is used to store original data and operation results, and the data will not be lost after a power failure; 2. Memory is characterized by fast access speed, but small capacity and expensive price, while external memory is characterized by large capacity, low price, but slow access speed; 3. Memory is used to store programs and data that the computer needs to use immediately. Memory is used to store programs and data that are not in use temporarily.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

What is memory?

Memory is a memory device used to save programs and data, as well as intermediate results and final results of operations.

Memory can be divided into two categories: main memory (referred to as main memory or memory) and auxiliary memory (referred to as auxiliary memory or external memory). It is the main memory that directly exchanges information with the CPU.

Internal memory and external memory

Internal memory refers to the main memory of the computer and is located between the CPU and the main memory. cache between.

Internal memory is mainly used to temporarily store instructions and data being used by the CPU. It has the closest relationship with the CPU. Because the programs and data it stores need to be used immediately, it requires fast access speed, and is usually composed of semiconductor memory. The CPU fetches instructions and stores data directly from the main memory. Information is not saved after power is turned off.

External memory refers to the auxiliary memory of the computer, including hard disk, floppy disk, optical disk, etc.

External memory is used to store information that is not needed immediately. Once needed, it can exchange data with the main memory in batches. It is used as a backup and supplement to the main memory. What exists is an external device to the host. It is characterized by large capacity and low cost. It can usually still save information after a power outage. It is a "non-volatile" memory, and most of the storage media can also save information offline.

The difference between internal memory and external memory

1. Internal memory is a temporary storage area when executing programs. All data will be lost after power failure; external memory is used to Those that store original data and calculation results need to be saved for a long time, and the data will not be lost after power failure.

2. The most prominent feature of internal memory is fast access speed, but small capacity and expensive price; the characteristics of external memory are large capacity, low price, but slow access speed.

3. Internal memory is used to store programs and data that are needed immediately; external memory is used to store programs and data that are not used temporarily.

Expand knowledge:

There are three indicators to measure memory: capacity, speed and price/bit. Therefore, the price per bit of high-speed memory is relatively high, so the capacity cannot be too large, so it must be divided into memory and external memory. The information being used is placed in the high-speed memory, and the temporarily unused information is placed in the external memory. But they are all computer storage systems, and they form a storage hierarchy. Overall, the computer has a speed similar to that of memory and a capacity similar to that of external memory.

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