Summary 📝

• The model is split into four layers: Application, Transport, Internet, and Link.
  
  

• Each layer handles different networking tasks, rom user-facing services to the physical hardware.
  
  

• Application layer: interfaces directly with software programmes (e.g. web browsers, email).
  
  

• Transport layer: ensures data is sent reliably using TCP or faster but less reliable UDP.
  
  

• Internet layer: routes data across networks by using IP addresses.
  
  

• Link layer: deals with physical connection and sending data frames over cables or Wi‑Fi.
  
  

• Data is wrapped in headers at each layer, and each layer at the receiving end unwraps it.
  
  

• Understanding each layer helps in grasping how internet communication works.