Konsole is one of the most important and helpful programs on a computer. Important because you can do just about anything with it and helpful for pretty much the same reason. It can be found in the Applications Menu under Applications/System/Terminal.
To be precise, Konsole is a terminal emulator running BASH (Bourne Again SHELL). A terminal is what you get when you strip away all the extraneous parts of a computer like the graphical user interface, etc... and end up with a black screen and a cursor. A shell is basically the system you use to put commands into the terminal.
For instance, if I type the command,
or copy and paste it for that matter the terminal will output,
which is the path to the bash program.
There are a number of commands that are used commonly in Konsole but the ones I tend to find myself using the most are,
apt - For installing and removing programs.clear- Clear terminal.exit - Exit terminal.ls - List the contents of the directory.cd - Change directory (cd .. to go up a level).sudo - run commands as admin or super user.top - See what processes are running (push q to end).
There is also another nice little trick you can do on KDE Neon that isn't really Konsole related but will give you an idea what the terminal is. KDE Neon is layered over the GNU programs which in turn are layered over the Linux kernel. We can swap to different terminals using Control + Alt + <F1 to F6> where F1 is where the GUI is. If the GUI crashes for some reason try changing to Control + Alt + F2, logging in, and doing some troubleshooting.
If that doesn't work you can always restart by entering,
sudo init 6