A simplified example of how the OSI model works, from this page:
For example: Mr. Cooper wants to send Ms. Palmer an email. Mr. Cooper composes his message in an email application on his laptop and then hits ‘send’. His email application will pass his email message over to the application layer, which will pick a protocol (SMTP) and pass the data along to the presentation layer. The presentation layer will then compress the data and then it will hit the session layer, which will initialize the communication session.
The data will then hit the sender’s transportation layer where it will be segmented, then those segments will be broken up into packets at the network layer, which will be broken down even further into frames at the data link layer. The data link layer will then deliver those frames to the physical layer, which will convert the data into a bitstream of 1s and 0s and send it through a physical medium, such as a cable.
Now that's fine, but a browser will first initialize communication with a server by agreeing in a cipher and encryption system (the "hello"). Could we say that when we press send, what first happens is that there is the hello from the client to the server, and that's how the session starts? I think I'm quite confused so any help is welcome.