While you are creating animations, you are actually creating animation keys for the parameters that are animated. The animation keys define how the values of those parameters change over time.
Each parameter that can be animated has its own list of animation keys, which is initially empty. In this case, the parameter just has a static value that is the same for the entire frame range, and it is not animated.
When you first change a parameter while Animate mode is on, Ultra Fractal inserts a new key for that parameter at frame 1 with its old value. Then, it inserts a second key at the current frame with the new value.
The time slider shows the keys as blue and yellow dots. Keys are displayed as yellow dots if they are located at the current frame. In this example, if you now move the time slider from frame 1 to frame 50, the parameter animates from its old value to the new value.
Next: Animate mode
Tutorial: Working with animations