The taskbar contains all the information about the programs that are running right now, and especially the Start button. This button gives you access to the programs installed on your computer.
Buttons on the taskbar show which windows are open, even if some are minimized or hidden under another window. You can easily switch to a window by clicking the corresponding button on the taskbar, if there is a need to switch between programs that are running using the keyboard, use the ALT keys + TABLE
Using the start button, you can perform almost any task. You can start programs, open documents, customize the system, get help, search for items, and more. Some Start menu commands have an ellipsis (...) indicating that before executing that particular command, Windows will prompt for user intervention.
Source: Brazil School - https://brasilescola.uol.com.br/informatica/barra-de-tarefas.htm