The Vegas concept of Event is a good one, because it differentiates between the actual media clip on the hard drive and what you are doing with that material on the timeline.
As soon as you drop something on the Timeline it becomes an Event. If you split this event, you will have two events, but the original media file remains unchanged – the timeline is just a reference to the media.
If you want to apply an effect such as brightness to part of an Event, one way to do this is to split it and brighten just the part that needs it. Another way is to use keyframes, but lets keep it simple and use splits for now.
You can reunite a split event by deleting one side of the split then dragiing the edge of the other till it fills the space formerly occupied by the deleted part. If you do this, though, the effect or lack of it will now apply to the whole event, unless you use keyframes to tell Vegas which part(s) you want to be affected.
Just applying a split will not affect continuous playback.
hth
Peter Wright
Perth, Western Oz
http://www.allroundvision.com.au