In this day and age, it’s common to see people with multiple-monitor setups. In fact, I’ve grown so dependent on the extra monitors that I almost hate working on my laptop when I travel. My multitasking skills just simply cannot be fully realized on a single screen. When I am at home, I like to make the most of the extra space. One way to do that is to get my taskbar to extend across all of the monitors. Sadly, this is not something that can be done without the use of extra software.
Dual Monitor Taskbar is a handy piece of software that adds a second taskbar to your other monitor. This can be used to organize your running programs onto different screens, or just duplicate the same ones on both. You can also pin different programs to the secondary bar, so that they are easier to reach when doing certain tasks. Dual Monitor Taskbar is also open source software, so it is completely free.
I've used UltraMon for a decade and love it.