I found a quick, but very cool overview of equalization (EQ). Not that I don't think my explanation(s) aren't the best :-). You can see my main one (also with a video that anyone can understand here: What is Equalization, Usually Called EQ?
The video (from the WinkSound YouTube Channel) shows you different kinds of EQ and goes over the parameters of each. It also goes over what controls are typically available (bandwidth - sometimes called "Q," frequency, amplitude, etc.) on different types of EQ units or plugins.
I know those terms might be confusing if you've never worked with equalization and frequency stuff before. But really - the basics are very easy to understand. If you're really just needing the starter primer basics, I strongly encourage you to watch the video on the post I linked to in the first paragraph above. I really do think absolutely anyone can understand it after watching that.
By the way, there are built-in EQ tools in both Audacity and Reaper recording programs (and pretty much ANY recording software, really), and we show you how to use them in both of our courses in the Newbies Guide To Audio Recording Awesomeness series (TNGTARA 1 uses Audacity and TNGTARA2 uses Reaper).
And without further ado, here is the video I initially mentioned from WinkSound: