Be Prepared to EAT the Giant TCP/IP Animal!!
An easy way to think about TCP/IP is that it is the language and transport mechanism of the internet.
What we mean when we say such a thing is that TCP/IP is an agreed-upon method of communication whereby all devices on the internet can communicate with other devices. Because we get tired of saying "agreed-upon method of communication" we use the word protocol instead. You and I agree that this is how we are going to communicate: regardless of the culture or language.
In actuality, TCP/IP is a very big, very complicated subject. TCP/IP is a suite of protocols: lots of them!
But here's the thing: If you're going to work in Information Technology (IT) - anywhere - you must know TCP/IP. It is simply one of those things you have to know.
This May Be Where YouTube Comes To The Rescue
So, there's this crazy man called Eli the Computer Guy (lower left). And he has some pretty good You Tube videos. The one linked here is a YT that he recorded talking about TCP/IP. It is over an hour long! Hopefully, you'll have an idea regarding what this topic is all about.
The second YT vid is from a group called TechQuickie. It too has some good information in it.
Oh...did I say this? You have to know TCP/IP like the back of your hand. Like cold, dude. Cold. PLAN ON IT!!