A brief explanation of the server

Simple understanding of the server

• We often use the database when we develop
• But you can never throw the database directly on the user's computer
• One is too big, the other is insecure
• So we have to put the database on the network from the other end (remote)
• Therefore, when front-end personnel request data from back-end personnel, the network is required
• It is impossible for us to put the page on the user’s computer
• So users also need the network to request pages from front-end personnel

Server awareness

• We have some common servers in the market that can host content
• At present, the more commonly used is ApacheandTocat
• The Apacheserver is explained here
• It is phpa server that cooperates closely with the language

What is a server?

• In fact, to put it bluntly, a server is a computer. When it runs some programs, it becomes a server.
• It’s just that you can run some special programs and need some special environment. The computer looks different from his.
• In other words, our own computer can also be used as a small server when running some special programs.
• It's just computing power, storage capacity, and transfer capacity. There is no professional server computer.

Server access method

• Related to urlsome content in our address
• Such as our frequently visitedwww.baidu.com
• What we see is just an omitted content
• It’s the browser that helped us omit some content
• All addresses should be:https://www.baidu.com:443
• Did you find two more things: https://and:433
• In fact, a simple urladdress is composed of three parts
  1. Transfer Protocol
  2. domain name
  3. The port number

Transfer Protocol

• Our common transmission protocol is httpandhttps
• They are the methods and rules that restrict the communication and transmission of data between the user and the server
• It is also the rule of interaction between our front-end and back-end personnel
• rule:
  1. Establish a connection channel
  2. Mutual communication
  3. Close the connection channel
• http: Is a common protocol, not very secure
• https: Is an encrypted transmission protocol, relatively safer

domain name

• As we said before, the server is a computer on the other end of the network
• In the past, there was no concept of a domain name, everyone used IPaddresses to access
• That 网络那一头is the computerIP
• For example:, 30.36.136.76is a bunch of numbers, not easy to remember
• There is a World Wide Web at the back , which iPmatches each address with an English name, which is convenient for users to remember
• So, on behalf of the domain name that a network that the computer's IPaddress
• In fact, which server we want to visit

The port number

• Other people’s server computers also have a lot of folders
• Different content is stored in different folders
• There may be a folder, which stores the homepage
• There may be a folder b, which stores some data
• So, you can’t just find the server computer, you have to find the right folder.
• Everyone numbered the folders and stored a 0-255total of 256 folders
• There are 0-255also 256 corresponding small folders in each folder
• Then there is 256*256a folder in total , which is from0-65535
• So we have one port number 65536, which corresponds to0-65535
• Everyone regards the 80port number as the default port number for a total of websites
• The http protocol defaults to port 80
• The HTTPS protocol defaults to port 443

Look at Baidu again

• Up to now, we are looking at the full url address of Baidu
• https://www.baidu.com:443
  1. Communicate with an encrypted transmission protocol
  2. Access is on the network IPvalue of 119.75.217.109that computer
  3. The visit is the first 443document folder
• This folder stores a Baidu page
• We can see this page when we open it