The main process

  1. [User] Enter the URL
  2. Browser Resolves the host name from the URL
  3. [Browser] Translate hostname to server IP address (DNS domain name resolution) – application layer

Search the local DNS cache list first. If no query request is sent to the default DNS server and cache it

  1. Browser Resolves the port number from the URL
  2. [Browser] Establishes a TCP connection with the target server (three-way handshake) – transport layer
  3. Browser Sends an HTTP request packet to the server
  4. [Server] Returns an HTTP response packet to the browser
  5. Close the connection and parse the document
  6. If there are other resources in the document, repeat 6, 7, 8 until all resources are loaded

Process details

TCP/IP traffic

The sending end goes down from the application layer, and the receiving end goes up from the link layer

URL

  • URI Uniform resource Identifier (URI) and URL Uniform resource locator (URL)
  • A URL is a subset of a URI

DNS

  • Provide domain name to IP address resolution service (search IP address by domain name or reverse search domain name by IP address)
  • Computers can be assigned IP addresses as well as host names and domain names, which are usually used (for easy memorization)

TCP

  • Data is divided into packet segments (the smallest unit of data transmitted over the network) for management
  • TCP verifies whether data is finally delivered (via three-way handshake)

IP

  1. The IP protocol is used to transmit data packets to the peer party. Two important conditions must be met to ensure that the packets are transmitted to the peer party: IP address and MAC address
* IP address Indicates the IP address assigned to the node. The MAC address is the fixed address of the nic. * THE IP address can be paired with the MAC address, and the IP address can be changedCopy the code
  1. The ARP protocol is used to communicate by MAC address
* COMMUNICATION between IP addresses depends on MAC addresses * ARP is a protocol used to resolve addresses. The CORRESPONDING MAC address can be traced based on the IP address of the communication partyCopy the code
  • On the network, the communication parties are rarely in the same LAN. Usually, they are connected to each other through the transfer of multiple computers and network devices. During the transfer, they use the MAC address of the transfer device at the next station to search for the next transfer target

Rendering process

Basic rendering process: 1. HTML parsing out DOM Tree 2. CSS parsing out Style Rules 3. 4. Layout calculates the information of each node according to the Render Tree. 5Copy the code