Introduction to Computer Science

Should be in many years ago the computer began to slowly popular, now still remember when I read junior high school, although only had two computer lessons, but I use Flash to do a round face animation, if always insist maybe I am now also famous big bull, but the reality is always very skinny ha.

Computers have developed rapidly in recent years, but think of my college days when I can only use the computer to watch TV and play games, the rest of the basic do not know, in order to help me like the “computer blind”, let’s take a look at some basic knowledge of the computer.

The purpose of the computer

Only when there is demand can there be corresponding products. For example, nowadays people seem to be getting lazy about cooking, so there are various delivery platforms. Another example is that nowadays people are more and more in pursuit of health, so there are many “vegetarian shops”. For example, there are more and more single people nowadays, so IF you are the One, I was watching it a while ago (PS: now I have a successful boyfriend, so now I don’t have this need)…

To sum up, it is because there are needs, corresponding products will appear, and computers can also be considered that some needs cannot be met only by human beings, so a new product is needed to replace human beings to perform certain functions. The purpose of the emergence of computers is to make them have certain functions of human beings. So when we understand the basic composition of computers, we can learn from some of the functions of humans, and maybe get twice the result with half the effort.

Computer hardware consists of five major components

Let’s take a look at the basic components of computer hardware.

As the figure above shows, computer hardware can be divided into five parts:

  1. Arithmetic machine: responsible for mathematical calculation and logical operations, just as people can do some operations;

  2. Controller: a system of command that controls all other components of a computer, just as all human activities are controlled by the brain;

  3. Memory: Divided into memory and disk, used to store data.

1. Memory: based on electricity work, power off the data will be lost, but access speed is very fast. For example, your girlfriend tells you their birthday, and then you remember it in your head, and then one day your girlfriend asks you her birthday, and it's time to test you, can you remember?? 2. Disk: Stores information permanently but takes a long time to read. Or the example above, you forgot your girl friend's birthday carelessly, how to do how to do, online wait, quite urgent.... So to be on the safe side or write it down in your little notebook, your own memory is not good, you have to rely on external forces, although a little slow, but the total is better than even the data have no good.Copy the code

  1. Input devices: the mouse and keyboard we usually use belong to input devices, just as human beings rely on eyes and ears to receive information.

  2. Output device: The display is an output device, just as the human will speak their own information through the mouth.

To summarize a little bit:

Together with the controller we call the CPU, the brain of the computer;

The memory is divided into memory and disk. Because the memory can input data (store data) and output data (the data in memory is output by the output device), the memory is also called IO(input output) device.

How does a program work

There are a lot of software on our computers, such as QQ, wechat, browser… These programs are installed on our computers, so why does a single click of the software or program work?

Actually we installed on the computer, the software is also some code, the code is our computer hard disk, when we double click to run the program, the CPU will control drive program data from the hard drive first loaded into memory, then the CPU in memory read the instructions in the program, completed a program launch.

So starting a program depends on at least three core components of computing -CPU, memory, and hard disk.

The operating system

When we buy a computer, the operating system has been installed on the computer, such as the current Win10 Linux system and Apple’s MAC OS system, both belong to the operating system.

What is an operating system?

Operating system is used to coordinate the control and management of computer hardware and applications of a control program, operating system is also a program, a little difficult to understand? In other words, if you want the various programs on your computer, such as QQ, to run normally according to the procedure we said before, you must rely on the operating system. Without the operating system, no matter how many CPU hard disks are installed on the computer, you can not double click the QQ program to run. Buy back no operating system of the computer basic can burn incense for up, joking…

What exactly is the operating system for? It can be divided into two aspects:

  1. Control the basic operation of the computer hardware, as we said above, when we double click to run the program is the CPU, and this brother in addition to the operating system, other software programs do not give a face.
  2. The complex operation of hardware is encapsulated into a simple function to upper applications use, we can understand the upper process to be like a running QQ WeChat above the operating system scheduler, when we use these programs, we don’t have to pay attention to how the computer hardware level works, need only pleasant chat with my little brother little sister.

The above is about the operating system some small knowledge, I hope you can understand oh!

Program division

Now that we’ve seen how operating systems and programs start, let’s take a look at how programs are distinguished.

There are all kinds of software installed on our computers, for watching TV, playing games, writing documents, looking at pictures… Here we will introduce how these programs are distinguished, programs can be roughly divided into two categories:

  1. Application: QQ netease cloud music youku, interesting life than our application which line, life or need appropriate entertainment.
  2. System procedures: operating system, without me, you can properly entertainment??

The three-tier structure of a computer

Here we have introduced the hardware and software of the computer, and how they roughly work. We can layer the computing hardware and the application, so that we can more easily understand the relationship between the computer hardware operating system and the application. I drew a simple picture of the relationship…

Is simply the application of a boot process, we use QQ WeChat belongs to upper application software, such as not directly call computer hardware, need with the help of the operating system, and the operating system can control the CPU to operate the computer hardware, so say, like the operating system plays a important role.

At the end of the article

The above is some basic knowledge of computing fundamentals. If you think my writing is good, please give a compliment. Welcome to follow my wechat public account for more python knowledge.

More wonderful python tutorial B stand, please focus on me: www.bilibili.com/video/BV1K8…