One 、 Basic structure of computer

1、 feng · Neumann model

（1） The computer hardware consists of the following figure Five parts form

（2） The idea of storing programs ： The running process of the system is the process of continuously executing the program instructions in the memory in a certain order .

2、 Memory classification

（1） Main memory is memory . The data to be processed in the program and the processing results are stored in memory
（2） External memory is mainly a large capacity memory used to keep data for a long time
（3） The register is CPU Internal high-speed memory , Fast width , The number is small

Two 、 What is a program

In a broad sense , A set of operable work steps designed in advance to achieve a specific goal , Call it procedure .
For computers , A program is an ordered set of instructions that can be recognized （ Binary ）. It is stored on disk and loaded into memory to execute .

3、 ... and 、 The development of programming language

1、 machine language

Direct use of machine instructions （0,1 Sequence ） To design programs , Can be directly recognized by the computer .
Bad for memory , Big workload .

2、 assembly language

Symbolize machine instructions , Machine instructions are represented by a simple set of symbols , Closer to natural language , Easier to use , But the workload is huge .
Great difference after changing the platform , Poor portability .

3、 High-level language

It has nothing to do with a fixed computer system , Closer to human natural language . One statement can correspond to multiple machine instructions , Little work 、 High development efficiency .

Four 、 Programming steps

edit （vi）-> compile 、 link (gcc)-> perform 、 debugging

5、 ... and 、 summary

This part is to simply understand , Later learning will be more in-depth ！