recordMyDesktop is an application that comes in two parts. These are the command-line program(the backend) and the graphical interface(the frontend). These are separate programs, but all the functionality relies on the backend which is also a standalone program. The frontend on it's own can't perform any meaningful operations.
Furthermore, the frontend comes in two versions. One written with the gtk toolkit (thus named gtk-recordMyDesktop) and a more recent one, written with the Qt toolkit (qt-recordMyDesktop). These two frontends derive from the same code-base with qt-recordMyDesktop being a port of gtk-recordMyDesktop. As a result of this, both frontends provide the exact same functionality through the exact same interface (with a couple of minor exceptions ). Thus the rest of the guide refers generically to these two interfaces as the frontend. Wherever there are differences there will be an appropriate note.
This guide explores using recordMyDesktop only through the frontend. If you want to use the backend alone, you should first consult the accompanying man page.
Also, while reading this document, you don't have to worry about memorizing anything, as the frontend will remind you with tooltips what every option is meant for. So if you are unsure of what a button or value represents, just hover your mouse over it and read the description.