Kawase blur effect
This is a faster version of the traditional "Blur" effect. It's recommended that you use this one rather than the "Gaussian" blur effect.
The Blur value sets the overall strength of the blur. Pixelize X and Pixelize Y let you stretch the blur along one axis only — for example, a horizontal or vertical motion blur. Increasing the Quality produces a smoother result at the cost of performance, so keep it low unless you need a very strong, clean blur.
Reference
All effects are listed in the effects reference page.