Photoshop Styles are a convenient way to stylize your layer/text/element/graphic. This is actually predefined settings about how an element will look like when you apply variant customization like gradients, drop shadow, texturing and many more. You can set your own customization or download following graphic styles. These Styles can be found(after installing) in your Style palette which can be applied on a layer/element with one click. You can tweak the settings if needed.