/just-express

Primary LanguageJavaScript

Express Course

Finished Github Repo

Pre Express

  1. HTTP -> TCP/UDP
  2. NodeJS Webserver
  3. Internet a network of nodes sending packets

Networks

Packets

  • Five layers to every packet
  1. Physical => Cables
  2. Link => WIFI/Ethernet |
  3. Network => IP |> TCP/IP
  4. Transport => UDP/TCP |
  5. Application => HTTP(S)/F(S)TP/SSH/SMTP

Your Webserver

Transport layer creates 2^16 ports ~65.000 Ports are like room numbers in a hotel WS: 49742 => SEGMENT => NETWORK
Destination port 80 UDP - lightweight/fast 8byte HEADER Source: 49742 - Connectionless - Consistency => sends data no matter what | UNRELIABLE TCP - Connection-Based | Three way handshake - RELIABLE 1. Delivery acknowledgement 2. Retransmission 3. In-order packets 4. Congestion Control

HTTP | part of the application/transportation layer

  1. Efficient
  • Only connected when required
  1. Stateless
  • No dialog | Everything forgotten after closing connection

HTTP

Start line - REQUEST => Method: GET | Protocol: HTTP/1.1 RESPONSE => Protocol: HTTP/1.1 | StatusCode 201 Header - Content-type: text/html

Body - Content