Open Systems Interconnection Model

Layer	Name	Role	Protocols	PDU	Address
7	Application	Initiates contact with the network	http, https, ftp, smtp	Data
6	Presentation	Formats data, optional compression, and encryption		Data
5	Session	Initiates, maintains, and tears down session		Data
4	Transport	Transports data	TCP, UDP	Segment, Datagram	Port
3	Network	Addressing and routing	IP, ICMP	Packet	IP
2	Data Link	Frame formation	Ethernet II	Frame	MAC
1	Physical	Data is transmitted on the media		Bits