An FTP server is a computer that provides storage space on the Internet and provides services in accordance with the FTP protocol. The full name of FTP is File Transfer Protocol. As the name implies, it is a protocol dedicated to transferring files. Simply put, the server that supports the FTP protocol is the FTP server.

In fact, FTP is a data transmission protocol, which is responsible for exchanging data on our computer with server data. For example, if we want to transfer the website program made in our computer to the server, we need to use the FTP tool to The computer is transferred to the server. Professionally speaking, FTP (full name: File Transfer Protocol) is a protocol for transferring files between two computers on a TCP/IP network. FTP is one of the earliest protocols used on TCP/IP networks and INTERNET, and it belongs to the application of network protocol groups. Floor.

The FTP client can issue commands to the server to download files, upload files, create or change directories on the server, and generally we transfer the content of our computer to the server data. In fact, the computer is the same as the server, except that the server system is installed on the server, and the stability and quality of the server are higher. Because the server is usually placed in a computer room such as telecommunications, it is turned on 24 hours, so that we can always access the server. Relevant information in .

In general, the primary purpose of user networking is to achieve information sharing. File transfer is one of the most important aspects of information sharing. The early implementation of transferring files on the Internet is not an easy task. We know that the Internet is a very complicated computer environment. There are PCs, workstations, MACs, and mainframes. According to statistics, computers connected to the Internet have been installed. Ten million, and these computers may run different operating systems, there are servers running Unix, PCs running Dos, Windows, Macs running MacOS, etc., and file exchange problems between various operating systems are required. Establish a unified file transfer protocol, which is called FTP. There are different FTP applications based on different operating systems, and all of these applications adhere to the same protocol, so that users can transfer their files to others or obtain files from other user environments.

Like most Internet services, FTP is also a client/server system. The user connects to the FTP server program on the remote host through a client program that supports the FTP protocol. The user issues a command to the server program through the client program, the server program executes the command issued by the user, and returns the result of the execution to the client. For example, the user issues a command asking the server to send a copy of a file to the user, and the server will respond to the command and send the specified file to the user's machine. The client program receives this file on behalf of the user and stores it in the user directory.

Above we briefly introduce what FTP is, but there is also an FTP server concept that you should not confuse. We can install the FTP tool on the computer to transfer the data from the computer to the server. This is called the FTP server, and our computer is called the client. Simply put, an FTP server is a server that stores files for users to upload or download files.

FTP is an 8-bit client-server protocol that can operate any type of file without further processing. It may not be well understood. The author gives you an FTP data transmission schematic:

FTP数据传输原理