OSI Model

The layers of the OSI model:

Application

Such as YouTube.com, or whatever program or website you are using

Presentation 

Session 

Like choosing which shipping company to use to send a packet

- some common protocols are L2TP, RTCP, H.2US, and SOCKS

Transport (have segments)

- can use TCP (slow but reliable) or UDP (fast but unreliable)

    -- TCP initiated with 3-way handshake: SYN, SYN-ACK, ACK

- common ports used are: 443 - HTTPS, 21 - FTP, 22 - SSH, 3389 - RDP

- may use ephemeral ports, which are like temporary addresses

Network (have packets)

Data Link (have frames)

Physical 

References:

Images and notes are taken from Network Chuck: 

How the OSI model works on YouTube (application and transport layers): https://www.youtube.com/watch?v=oIRkXulqJA4