Sliders are gadgets in Geogebra (or any similar software) that allow you to change the value of a variable in an equation without having to change the variable by hand multiple times. You simply "slide" the button and the value of the variable changes as does the corresponding graph.
Creating sliders is rather easy. Just follow the set of steps below and you'll be graphing exponential functions in no time.
1. Open Geogebra and select the slider button.
2. Click anywhere on the graph section of Geogebra. You can move the slider
later if it is in the way. You can name the slider anything you want, but in
this case, name it "b" and select Apply.
3. Now type an exponential function into the input bar in the form y=b^x.
4. You can now use the slider to change the value of the base. It is important
to remember that you must select the "Move" icon to change the value
of the slider.
5. Now continue the exercise using the Graphing Exponential Functions OneNote and add additional sliders as indicated.
If the written description of how to do this is too much, try watching this video.
Source: Christian Henzler
If you are still lost after creating your own sliders, this may be a good resource for you.
Source: Khan Academy