What displays the clock and commonly used programs?

The answer is display device where a presentation of devices is shown for easier access.  It can be a displayed visual information. The presentation is an electronic display. This feature can be found on laptops, computers, televisions, and cell phones. 

Another is the taskbar on a computer or laptop. A task bar contains important icons also the clock. It also gives convenience to the user. 

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)