Multitasking

Insufficient information about what you want.

By default the keyboard and mouse only send information the front most window. Other windows can be doing things in the background while your attention is somewhere else, but if they also need your keyboard/mouse attention, it is difficult to be in 2 places at once.

If you give us an idea of what you want to do, maybe some examples of the apps you want to multitask and doing what with each concurrently, it might make it easier to come up with an answer.

Ágikám wrote:

Hi! I would like to know how I can work on several windows on the same time?

Guess: Are you using full-screen applications? If so, then switch out of the full-screen with the applications that you are using. If each application you are using is an entire screen, then you can move the cursor into the extreme top of the application display, where you should see an animated menu bar drop down and a blue box with two arrows displayed on that menu bar in the upper right corner of the display. If you do see that animated menu bar dropping down when the cursor is placed at the top of the display and if you then see that blue box in the upper right, move the cursor over and click on that blue box to switch to the not-full-screen mode.

Alternatively (if your applications are in full-screen mode), then you can press the control key and the command key and the F key as a chord, and that will also exit full-screen.

If the above (guess!) is not the behavior that you are seeing, then please provide a few more details on your quest and what you're currently seeing.