Great Question!

Thank YOU JENNIFER!!!!
I need feedback and I love questions and this morning Jennifer had a great one - What is a brush?

I hope that she doesn't get mad - But I am just going to post a little bit from her e-mail.
I guess I'm still a little confused what brushes are to start. Is that flower thing is that an image you started with or is it a brush? Is a brush kind of like a stamp?

Yes - the flower is a brush.
I wanted to tell you that a brush is very similar to a stamp in traditional scrapbooking. You can "stamp" a brush or you can paint with a brush. In the technique that I did the tutorial for - we are "stamping" more than we are brushing. Brushes themselves come in many forms - flourishes, Alphas, Dingbats and traditional strokes.

Here is a link to Scrap Girls Brushes - you will find all sorts of goodies - like words and quotes too!

If we think of this type of BRUSH technique as STAMPING - we control the amount of INK we put on the brush by adjusting the Opacity and Flow(in CS3). For my additive technique - I set my brush to 100% opacity and for my subtractive technique - I adjusted the opacity. I stated arounf 65% and moved it down every few mouse clicks. Not being a traditional scrapper and NEVER having stamped - I think that the subtractive technique is one of the benefits of digital scrapping - but like I said - I really wouldn't know the traditional method for this.

When we talk about STAMPING in Photoshop - we are talking about using tools like the healing tool for retouching image or cloning to remove an unwanted object. We can discuss those too if anyone is interested?

Let me know if this helps :D