Effects
The generic term "effect" is used to mean both spells that help (buffs) and spells that harm (debuffs). It's just easier than typing "buffs/debuffs" everywhere. An aura is the specific term for an effect that has no duration or is in effect until it is cancelled, and can be a buff or a debuff.
Buff Frames
A buff frame is a frame that holds effects. Simple, yes? With SBF, you can define as many frames as you want to, as opposed to the default UI's basic two. You can change each frame's scale individually, make it more transparent, and there are a lot of doodads to let you arrange the way the effects will show up in it. Once you have frames, you need to get effects to show up in them - that comes later.
Icons and Timers and Bars, Oh My!
The basic default SBF display is the effect's icon with a timer below it, similar to the default UI with timers enabled. There are 5 possible elements for a effect:
Filtering - it looks complicated, but it's not!
Filters let you assign rules to get effects into the various frames you create, instead of selecting each and every effect and using Show in Frame. For example, you can make all effects with the word Elixir in their name go to a particular frame, or effects whose duration is greater than 20 minutes to another frame. You can even make all effects with less than 30 seconds duration remaining go into some frame, but check out the Filters page about that and other filter topics.
Flowing
Flowing lets you easily move effects from one frame into another - without mixing them with the effects of the destination frame. All of the sorting and expiry options of the original frame are retained, and the flowed effects appear after the effects that normally appear in the destination frame. A common use of flowing is to make all debuffs appear after buffs in one frame. See the Flowing page. Note: Flowing happens after show in frame and filtering is applied.