URI / URL

How Internet Works

Internet is a global network of interconnected computers that communicate using standardized protocols.

Key Components

• Clients and Servers
• Protocols
• IP Addresses
• Domain Name Systems(DNS)

A Web Request's Journey

• Step-1: Entering a URL
• Step-2: DNS Lookup, DNS Server Interaction
• Step-3: Establicshing a TCP connection
  • browser sends a TCP SYN (synchronize) packet to the server.
  • server responds with a SYN-SCK (synchronize-acknowledgement) packet.
  • browser sends an ACK (acknowledgement) packet, completing the three-way handshake.
• Step-4: Sending an HTTP Request
• Step-5: Server Processing and Response
• Step-6: Rendering the Webpage

URI & URL

URI (Uniform Resource Locator)

Components:

• URL (Uniform Resource Locator)
• URN (Uniform Resource Name)

Components of a URL

• Scheme
• Host
• Port
• Path
• Query
• Fragment