Screen capture allows to store what is shown on the screen and might come with the desktop environment. The following are options independent of the desktop environment.

There is a desktop file around that just calls: lximage-qt --screenshot

lximage might already be nsttalled on the system (maybe even with this desktop file)

Instead of using something special use gimp. File -> Create -> Screenshot then the screenshot appears in gimp ready for adding additional items, editing and saving.

shutterbug is a nice featured screen capturer that comes with fox and has not many dependencies.

scrot is a command line tool. Starting scrot will capture the complete screen, scrot -s pops up a mouse cursor to select what should be captured. man scrot shows all the other options.

To store what happens on the desktop to a movie:

simplescreenrecorder is a simple gui based screen recorder that does job well with many options. Since the gui is simple it does more than one would expect.

gtk-recordmydesktop, qt-recordmydesktop or its backend recordmydesktop. The window pops up where inside the screen is seen. Inside this window the area or window to be recorded can be selected. When start recording, the window disappears. To stop the recording a button in the status bar is visible. Once captured the raw data is encoded and can be stored per default in the home directory.