Hard disks, floppy disks, memory, external memory, what are the differences and connections

The hard drive is inside the computer.

A floppy disk is a disc-like disc that can be carried. But now there are fewer people who use floppy disks!

Hardware is generally known as something that can be seen and touched, such as a host, a monitor, and so on.

Software is something that can't be touched, such as your QQ, online games, etc.

Memory is part of the hardware.

As for the outer memory you mentioned, I haven't heard of it.

All the data of the computer has to go through the memory to be processed by the CPU first, but the data in the memory cannot be saved after the power is off, and the memory only stores the data temporarily.

External memory is relative to memory, hard disks, floppy disks, optical disks, and U disks are all external memory, and the data will not disappear after power failure under normal circumstances.

Many friends must have heard of these 4 concepts, especially hard disk and memory. There are two parameters that must be considered when we buy a computer, that is, the size of the memory and the size of the hard disk, generally speaking, the larger the memory, the faster the computer will run, and the larger the hard disk, the more files can be stored. In this way, it seems that hard disks and memory have nothing to do with each other, but in fact, whether it is memory and hard disks or floppy disks and disks, they are essentially used to store data.

Since they all store data, why are there so many categories?

Let's start with the relationship between disks, hard disks, and floppy disks. In fact, hard disks and floppy disks are both disks, and they are both external storage (external memory is characterized by not being affected by power outages). So what's the difference between a hard disk and a floppy disk?

Hard disks are generally installed in the chassis, which have a relatively large capacity and can store more files. The floppy disk is not installed in the computer, but removal, generally used to store files and copy files between different computers, in terms of function, it is the same as the current U disk, but the shape, storage principle is different, its capacity is much smaller than the hard disk, such as the most commonly used inch floppy disk capacity only, such a small storage space for us basically can't do anything, and its storage speed is much slower than the hard disk. So only early computers would use floppy disks, which have now been phased out.

As mentioned earlier, there must be internal memory, and every mistake, this is what we call memory. The storage speed of the memory is much faster than that of the hard disk, but the memory will be affected by the power failure, which means that all the data stored in it will be lost once the power is off. Presumably everyone has experienced such a scene, just when we were buried in work, there was a sudden power outage, and at this time, someone must have shouted "It's over, it's over, the xx I just made hasn't been saved".

In fact, these unsaved data are temporarily stored in the memory, and will be lost once the power is off, and will only be permanently stored in the disk after we click the save button.

Hard disks are external memory. The differences are as follows:

First, the reference is different.

1. External memory: External memory refers to the memory of Luxun in addition to the computer memory and CPU cache of Huihan, which can still save data after power failure.

2. Memory: also known as internal memory and main memory, its function is to temporarily store the computing data in the CPU, as well as the data exchanged with external memory such as hard disks.

Second, the characteristics are different.

1. External memory: It is characterized by large capacity and low capacity, but the access speed is slow.

2. Memory: It is characterized by fast access speed, but small capacity and high price.

Third, the use is different.

1. External memory: used to store those programs and data that need to be used immediately.

2. Memory: used to store programs and data that are not used temporarily.

Difference Between Memory and Hard Disk:

First, the nature is different.

Memory is the workplace of the computer; Hard disks are used to store information that is not in use for the time being.

Second, the production materials are different.

Memory is made of semiconductor materials; Hard drives are made of magnetic materials.

3. Information retention is different.

Information in memory is lost when the power is lost; The information on the hard drive can be stored for a long time.

Fourth, the capacity is different.

Generally, the capacity of hard disks is 1TB, that is, 931GB; Whereas, the memory is generally 6GB.

Fifth, the role is different.

Memory is a buffer between the CPU and the hard disk data, and the CPU can only read the data in the memory. In this way, memory becomes a bridge; Whereas, hard disks are used as storage space.

They are both storage devices, and they are both used to store data, so what exactly is the difference between them?

The computer relies on the CPU to process data to work, and most of the data is stored on the hard disk, so when the computer is working, the CPU and the hard disk need to cooperate very well, so that the computer will be very smooth; However, because the working frequency of the CPU is quite high, and the work efficiency of the hard disk is relatively low, if the CPU shares and directly reads data from the hard disk for processing, the hard disk will not be able to keep up with the rhythm of the CPU, resulting in idle CPU resources. For example, it takes 1 second for the hard disk to read a certain data, and it only takes one thousandth of a second for the CPU to process the data, and then spend the rest of the time waiting for the hard disk to read the next data. The whole process is consumed on the hard disk reading the data, and the CPU actually has very little time to process this data, and most of the time is waiting for it senselessly, which obviously causes a great waste of resources.

To solve this problem, memory came into being.

Memory is also a storage medium, but its efficiency in reading data is much higher than that of hard disk, which better adapts to the needs of the CPU, thereby improving the running capacity of the computer.

With hard disk and memory, the working process of the computer is as follows: all the data is still stored on the hard disk, but some data that is in use or used in a particularly high rate is copied to the memory as needed, and the CPU processes the data directly from the memory instead of going through the hard disk.

If the memory is so good, what do you need a hard disk for? Although the work efficiency of memory is excellent, due to the complex technology and expensive cost, it cannot reach the storage capacity of the hard disk, and can only be responsible for some temporary storage, so the hard disk is also irreplaceable by memory.

Finally, let's take that classic example. The CPU is like a workshop, responsible for production and processing, and the hard disk is a raw material warehouse, which is very large and can store a large number of raw materials, but it is far away from the workshop, and it is very inconvenient to transport it back and forth. At this time, a temporary transfer station was built near the CPU, which was the memory.

Although he is not as big as the warehouse, he is close to the workshop, which stores the raw materials urgently needed by the workshop, which improves the production efficiency.

1. The hard disk belongs to the external memory of the town. The differences are as follows: refers to different external memory: external memory refers to storage other than computer memory and CPU cache, which can still store data after a blind power failure.

2. Hard disks and floppy disks belong to storage devices, and floppy disks belong to external memory. Floppy disks (floppydisks) were the earliest removable media used in personal computers (PCs). The reading and writing of floppy disks is done through floppy disk drives.

Floppy disk drives are designed to accept removable floppy disks, and the most commonly used one is a 5-inch floppy disk with a capacity of 44MB.

3. Hard disk belongs to external memory, and hard disk is one of the most important memories in the computer.