What's the difference between a computer hard disk and memory? What are the advantages of adding memory to a computer?

What is a hard drive?
A computer accessory used to store data. Non-volatile storage, to put it bluntly, even if you turn off the computer, the data inside will not be lost. Usually C disk, D disk, E disk in the computer, all refer to the hard disk. The exterior is a square box that contains the platter (like a disc), and the magnetic head that reads and writes the platter.
What is memory?
Because the hard disk speed is relatively slow, if the CPU runs the program, all data is read and written directly from the hard disk, which will greatly affect the efficiency. Therefore, the CPU will use the data to run the software from the hard disk to the memory at one time, and then the CPU and the memory for data exchange. Memory is volatile memory, as long as you lose power, the data in memory is gone. The memory itself is an integrated circuit board with several chips for storing data. Since this circuit board is generally made into a long strip, it is called "memory bar".
The difference between hard disk and memory
1, the definition of different purposes
Solid state drives are storage devices, and memory sticks are transit devices.
2. Storage of things
The SSD stored in its internal things will not be lost after the power failure, and the memory power failure after the restart information is no more
3 foreign
A solid state drive is a cuboid device, while memory is a long strip device
4. Interface
The interface of solid state drive is divided into power interface and signal interface. The memory bar is the connection between the Goldfinger interface memory and the hard disk
The information on the hard disk is always temporarily unused, in order to use the information on the hard disk, you need to insert the memory. There is no direct data exchange between the CPU and the hard disk, the CPU only commands the hard disk through the control signal, and the information on the hard disk can only be processed after being loaded into the memory.
What are the advantages of adding memory to a computer
New system software needs memory to run, which means that the more memory you have, the more software you can run simultaneously. Usually in the process of using the computer, if the use of software is stuck, this is caused by insufficient memory. Therefore, adding memory strips can effectively prevent memory stalling.
How to choose a notebook memory bar
1, we need to find out whether our notebook supports low voltage memory, or standard voltage memory
Notebook low/high voltage version at the time of purchase, we should know this problem. But it may take too long to forget. We can use Master Lu to see whether their laptop CPU is a low voltage version or a standard voltage version. Low voltage version of the CPU, certainly the notebook is also a low voltage version, the memory has to be low voltage, and the standard voltage notebook has to be standard voltage memory. Or through Master Lu directly look at the original memory, with DDR3/4 behind the L is the low-voltage version, without the standard voltage version
2, see how many memory strips the notebook supports, how much capacity
This is common sense. The notebook only supports 8G single root, you can not choose 2 4G, it is impossible to go to a single 16G. But there are plenty of them, too. Now many people shop, only look at the price or parameter performance, but do not do other homework, a word to eat, buy buy buy, bang bang.
3, see how many generations of notebooks support DDR, and the frequency of support
4. Look at the brand
If your laptop brand is relatively niche, then it is recommended that you be more cautious. Because you're more likely to encounter compatibility issues. In order to be safe, you can choose the same brand as the original memory module of the notebook when selecting the memory module.