abbreviation full form: Open Systems Interconnection (OSI)
is divided into 7 layers
the first
the 7 layers:
Physical layer:
what it does: sends raw bits over a medium like cables, hubs and other stuff
mainly focuses on the signal transmission itself not the data
Data link layer:
what it does: takes care of the node to node connection and correction plus framing as well through switches and node to node data transfer, error detected bridges
has two sub layers: (will look into it later)
Media access control (MAC)
Logical link control (LLC)
Network layer:
what this one does: handles packet routing and stuff like logical addressing (for example IP addresses). basically determines the best path for data to travel from source to destination
Transport layer:
takes care of the data transfer along with error recovery, segmentation and flow control
UDP : connectionless but less reliable data transfer
Session layer:
manages the establishment, management and termination of sessions (connections) between apps
Presentation layer:
translates data between the network and the application. basically takes care of the data encryption, decryption, compression and format translation. Otcp
ensures the data is in a usable form between layers