Apps pinned to the taskbar will always have their buttons show on the main taskbar. You can select to show taskbar buttons on all taskbars, main taskbar and taskbar where window is open, or taskbar where window is open. Starting with Windows 10 build 14328, if you have multiple monitors and your taskbar set to show on all displays, the clock will now be visible on each taskbar. These taskbars do not have the clock and notification areas on them. The other taskbars are the ones that show on the other displays that are not set as your main display. The main taskbar is the taskbar with the clock and notification area on it, and is on your main display by default unless you move the main taskbar to another display. If you have more than one display connected to your PC, then you will be able to hide or show the taskbar on all displays. You can make the taskbar look how you want, manage your calendar, pin your favorite apps to it, change the size, change location on screen, and specify how taskbar buttons group together when you have more than one window open. You can also see the date and time, system icons, and items running in the background on the notification area. The taskbar allows you to find, see, open, and switch between your apps.
Windows includes a special application desktop toolbar called the taskbar that shows on the bottom of a display screen by default. How to Hide or Show Taskbar on Multiple Displays in Windows 10
