I'm learing about the OSI reference model in my networking class, and the layers and examples all seems a little vague to me.
For example, I've learned that HTTP is one protocol that operates at the application layer. I know in definition what HTTP is, and why it is needed. But where is it located? Take the firefox application for example. I can find where it installs to, and know that firefox.exe is the main program. But what about protocols? Are they files that programs use? Do programs install their own specific protocols? Where are they?