Open Systems Interconnection (OSI) is reference model for how applications can communicate over a network.

There are 7 layers of OSI Model:

-Layer 1: Physical
Layer 1 conveys the bit stream (electrical impulse, light or radio signal) through the network at the electrical and mechanical level.
Protocols: Wi-Fi, Telephone network modems

-Layer 2: Data Link
Layer 2 sets up links across the physical network, putting packets into network frames.
Protocols: Ethernet, Virtual Local Area Network(VLAN), Media Access Control(MAC)

-Layer 3: Network
Layer 3 provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node.
Protocols: Internet Protocol version 4(IPV4), Internet Protocol version 6(IPV6)

-Layer 4: Transport
Layer 4, provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer.
Protocols: Border Gateway Protocol(BGP), Fibre Channel Protocol(FCP)

-Layer 5: Session
layer 5 establishes, manages and terminates connections between applications. The session layer sets up, coordinates, and terminates conversations
Protocols: Zone Information Protocol(ZIP), Network File System(NFS)

-Layer 6:Presentation
layer 6 provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa.
Protocols: Transport Layer Security(TLS), Apple Filing Protocol(AFP)

-Layer 7: Application
Layer 7, supports application and end-user processes.
Protocols: Hypertext Transfer Protocol(HTTP), Hypertext Transfer Protocol Secure(HTTPS)