BUTTONS: It's more instructive to find out what they do by clicking on them than by reading help files.
SLIDERS: There are several ways of changing the value of the variable controlled by the sliders. Putting the mouse cursor on the box in the center (the slider "handle"), holding down the left or middle mouse button, and dragging the mouse will change the value. Clicking either of these mouse buttons in the gray bar containing the box will move the box towards the cursor by 10% of the full range; and clicking either of the small triangles will move it by a smaller increment.
The value can also be changed by typing in the entry box over the slider, which
displays the current value. To put the "keyboard focus" in the entry box so that you can type in it, click the left mouse button in the entry box. When the number in the window is changed, the text turns red to indicate that the current value of the variable does NOT equal the number in the box. To change the variable, press
Double clicking with the left mouse button selects everything in the entry, so what you type will replace it.
The slider handle can be pulled beyond the range of the gray bar to set values outside of the nominal range of the slider.
Clicking in the rectangular box at the right end of the slider gives a configure window for the slider. Here you can change the range and size of the small incremental steps for the slider.