What is memory, external memory, main memory, and secondary memory

Memory is one of the most important components of a computer, and it is the bridge that communicates with the CPU. The running of all programs in the computer takes place in memory, so the performance of the memory has a very large impact on the computer.

Memory, also known as internal memory, is used to temporarily store computing data in the CPU and exchange data with external memory such as hard disks. As long as the computer is running, the CPU will transfer the data that needs to be calculated to the memory for calculation, and when the operation is completed, the CPU will send the result out, and the operation of the memory also determines the stable operation of the computer.

Memory is made up of parts such as memory chips, circuit boards, gold fingers, etc.

External memory refers to storage other than computer memory and CPU cache, which can generally hold data even after a power failure. Common external storage includes hard disks, floppy disks, optical discs, USB flash drives, etc.

Generally speaking, main memory refers to memory; However, in some more professional occasions, there is still a certain difference between main memory and memory. There are other forms of memory storage.

Memory and main memory in the CPU are two concepts; The processor needs its own internal memory, which exists in the form of registers.

Secondary memory is a hard disk in a narrow sense. Scientifically speaking, it is external memory (with which data needs to be exchanged through an IO system, also known as secondary memory). Large storage capacity, low cost, slow access, and the ability to permanently save information offline.

It mainly includes magnetic surface memory, floppy disk memory, tape storage device, and optical disk storage device.

External memory is auxiliary storage.

External memory refers to optical discs, floppy disks (inch floppy disks and inch floppy disks), USB flash drives, various memory cards and portable hard disks. This description of yours is correct.

You may be confusing RAM + external memory with ROM + RAM.

ROM represents read-only memory, that is, it can only read out information, can not write information, the information in it is still saved after the computer is turned off, and it is generally used to store fixed system software and fonts.

RAM represents read-write memory, which can be used for read or write operations by any of the storage units, and the information in it will not be saved after the computer is turned off, and it needs to be reloaded when it is turned on again, and is usually used to store the operating system, various running software, input and output data, intermediate results, and exchange information with external memory.

Nowadays, ROM is generally used in mobile phones, and RAM is what we usually call memory.

Memory alone doesn't seem to be classified as such!! You can be clear!!

The main memory is also memory, which can be directly accessed by the CPU, and is composed of RAM and ROM for fast read and write operations. Used to store running programs and data, it's fast but costly.

The auxiliary memory cannot be directly accessed by the CPU, and is used to store those programs and data that are not used temporarily.

Main memory generally refers to computer memory, auxiliary memory generally refers to external memory, such as hard disks, optical discs, etc., fast storage is not very clear, maybe you mean cache, generally integrated on the CPU or motherboard, faster than memory, but the cost is high.

When the secondary memory is powered off, the data will disappear, but the main memory will not.

Main memory(memory) withSecondary memoryThe differences (external memory) are as follows:

1. The difference between storage time:1. Memory has the advantage of time and speed;

2. The storage time of external memory is slow.

2. Difference in storage capacity:1. The memory capacity is small, and the general memory is 4G 8G.

2. The external memory capacity is large, and the rock capacity can be expanded through the external memory.

3. Difference in storage duration:1. The memory will not be retained after power failure.

2. The external memory can be retained for a long time.

Four-chain imitation, access rights difference:1. The CPU can only access the memory directly.

2. The external storage cave must be processed by the memory CPU first.

It's memory.

The main memory generally uses semiconductor memory, which has the characteristics of small capacity, fast read and write speed, and high quality compared with auxiliary memory. The main memory in a computer is mainly composed of five parts: the memory body, the control circuit, the address register, the data register and the address decoding circuit.

The total number of storage units that fit in a memory is often referred to as the storage capacity of that memory. The storage capacity is expressed in terms of the number of words or bytes (b), such as 64k words, 512kb, 10MB. In order to represent a larger storage capacity, units such as MB, GB, TB are used.

Among them, 1KB = 2 10B, 1MB = 2 20B, 1GB = 2 30B, 1TB = 2 40B.

It's memory.

The main memory is used to store instructions and data, and can be accessed randomly directly by the ** processor (CPU).

In order to improve performance and take into account reasonable cost, computers often use multi-level storage systems. In other words, the main memory with a small storage capacity and high access speed is indispensable due to the high storage capacity, and the main memory with moderate storage capacity and access speed is essential.

The main memory stores information by address, and the access speed is independent of the address. A 32-bit (bit) address can express a memory address of up to 4 GB.

Memory can be divided into primary memory (memory) and secondary memory (external memory).

Memory is the module that provides cache space at runtime.

What the previous one said is incorrect. A hard disk floppy disk can only be said to be a computer's memory, not memory.

It is memory, and generally hard disks and floppy disks are considered to be the memory of computers.

1> Main Storage:

It can be understood as the "hard disk" on our computer host, and the things we need to save for a long time are stored on it, because it belongs to the surface of the ROM after power failure, and the stored data will not be lost.

2> Memory:

He is RAM (Random Read-Write Memory).

Compared to the hard disk, its input and output speed is much faster, because the ALU (virtual register) in the CPU is faster than the hard disk, so it needs memory to communicate between the CPU and the hard disk.

To put it simply, memory acts as a bridge.

3> External memory:

Like optical discs, flash disks (USB disks), these are all external memory (storage).