There are actually five different gradient styles to choose from which are: Linear gradient, Radial gradient, Angle gradient, Reflected gradient, and Diamond gradient. The different gradient styles are shown in the diagram below accordingly:
Starts from one point to another in a straight line.
Starts from one point to another in a circular pattern. The first point is the centre of the gradient.
Starts in an anti-clockwise around the starting point. The size of gradient you drag marks the direction of the colour.
This gives a gradient from both sides the starting point, so you should get three stripes of colour with two colours being the same.
This gives a diamond shaped gradient.
You can also choose the blending mode and opacity for each gradient. The reverse can be checked which reverses the order of the gradient. You can create a smoother blend by selecting the Dither. And finally set a transparent mask by checking the transparency option.