You can move colours around and you can move the location slider (the slider above your gradient instead of it being below and which indicates the point where you are using 50% of the two colours making up the gradient), you can change the gradient from linear to radial and you can change its angle. Then you apply that gradient to an object the same way you would apply a colour and you can drag it in an out of your Swatches palette the same way you would do with a colour. You can apply gradients to both fills and strokes.

