This is a really good question, and honestly I didn’t really know what it was for most of my life either. If you had asked me what HTML was, I truly would have had no clue. I’m a little embarrassed now about that, but I have gotten over it. Ultimately, it’s really simple. I found a good resource here (http://www.brevedy.com/2014/03/17/what-is-coding-for-non-coders/). Let’s take a look at something simple like HTML, which technically is a markup language and not a coding language. You can use HTML to tell the browser how you want a webpage to be structured. You can say, hey browser, I want to have about an inch of space here after this paragraph. There is a syntax in HTML that allows you to do this. You basically write the code in a certain way to tell the browser what to do. If you want to make a link, you just need to know the special code for any link. Then once you have that down, you’ll be doing HTML in no time.
CSS is similar. You basically tell the browser how to style a webpage. It’s a little more complicated than that, but overall it’s not really complicated. If you want to make a picture look like a circle, you just need to know the code in CSS of how to do so. It’s really that simple.
Actual programming is a little more complicated. You give commands or inputs, and then the program gives you an output. You could ask the user his age, and then tell the program to give a certain message back to them based on their answer. That’s what coding and programming allows you to do. You give the program a situation and then tell it what to do in various situations.
Hopefully that gives you a decent idea of what coding is. If not, you’ll just need to dig into it a little bit and maybe do some practicing. You can certainly jump onto youtube and see a whole bunch of videos on the subject.