SerwerWeb.pl

Kazam is one of the best screen recorders for Linux. I've been using it for years. All video tutorials on YouTube were recorded with Kazam.

Some of the main features of Kazam are:
Record your entire screen, part of the screen, application window or all screens (in the case of a multi-monitor configuration)
Take screenshots
Support for keyboard shortcuts to easily pause and resume while screen recording
Record in various file formats, such as MP4, AVI in inside.
Capture sound from speaker or microphone while screen recording
Broadcast live video to YouTube
Below is how to install it.

Older version of Kazam is normally available in Ubuntu's software manager.

If we want to install the latest version, we will add a repo from the console and install it.

We start the terminal and issue commands:

sudo add-apt-repository ppa:sylvain-pineau/kazam

sudo apt-get update

sudo apt install kazam 

We also need to install some libraries, to record mouse clicks and keyboard presses.

sudo apt install python3-cairo python3-xlib