Widget Variations allow for the individual styling of each widget within a position, without it being global. Code wise, this is achieved by selecting a variation from the Widget Variation field in the Widget settings. The theme CSS adjusts accordingly.
There are 13 variations: title1-5, box1-3; flush, flushtop, flushbottom; plus standardcase and lowercase.
The Title suffixes control the styling of the widget titles, matching the various article styles available, varying in shape, color and format. The Box suffixes change the background styling of the widget, matching the settings in the Color Chooser. Remember, you can always combine suffixes together such as title2 box2, which will produce a colored widget title, with a colored background.
Flush will disable all padding and margin to the widget for a tighter fit, with FlushTop and FlushBottom disabling the margin/padding for the Top/Bottom parts of the widget respectively. StandardCase changes the title case to standard, with LowerCase change the title case to lowercase – Uppercase is standard, so no suffix required.