First of all, to put it simply: OSI reference model is an academic and legal international standard, and it is a complete and authoritative network reference model.
TCP/IP reference model is a de facto international standard, that is, a network reference model widely used in real life.
How did this happen? Slowly think:
As early as the 1970s and 1980s, the Internet began to develop. At the beginning, various manufacturers went their own way and produced many different networks, which were incompatible with each other. So, an organization called the International Organization for Standards came out and said: We should set an open standard for the Internet. As long as everyone follows this standard, the products produced are compatible with each other, so that consumers are satisfied and everyone has meat to eat. . This idea has also been supported by everyone. . Therefore, this organization organized a group of network experts to study some principles and solutions of network communication. As we all know, people who engage in academics have a bad habit of procrastination. They worked for many years and finally came up with OSI. This OSI is not built, and it is very thorough and authoritative in studying network communication problems. Experts are very satisfied, but they are also surprised to find that there are many network products in use all over the world, and none of them follow the OSI standard. What's going on here? Originally, the International Organization for Standardization said that an open standard would be issued, and those manufacturers supported it at first, just waiting for the result. As a result, after waiting for a while, I always find that there is no standard, but in reality, the development and demand of the network wait for others. . What should I do? Let's cross the river by feeling the stones. . This stone is the TCP/IP reference model. This is a very snobbish model. This paper mainly studies some problems in network interconnection. Any problems in the process of network connection can be considered and solved, that is, let reality correct them. In a few years, the manufacturers found that this TCP/IP was also quite easy to use, so they occupied the whole market. When OSI came out of the lab, I found that the real world had been occupied by TCP/IP. I wanted to appeal to manufacturers to use OSI standards, but no one listened. .
So, this is the situation now. .