Many years ago, we’d use gtkrecordmydesktop or istanbul to record the screen actions as we worked on the screen. Of the two, istanbul is no in the Ubuntu distribution. Gtk RecordMyDesktop is very much there, but it is a bit unwieldy in terms of features.
Therefore, the best utility today is VokoSreen. To install it, open a terminal window and enter following command:
$ sudo apt-get install vokoscreen <enter>
Vokoscreen is installed and is very easy to setup and use. It generates an mkv file and is very fast at doing so.