When using photo manipulation what does the term brush refer too.?

Question

Can somebody please explain to me what the term brush (in a program like Photoshop or GIMP) means in photomanipulation. What I thought it meant was literally a brush but then when you read tutorials on deaviantart the tutorial describes a brush that was bird (?!?!?!?!) or a brush that lightning, I dont know if I'm totally misunderstanding or misinterperting what is being said but I really would like the term to be clarified.

Answer 1

It means the shape of the tool used for making the strokes.  It is a bit un-natural, since shapes are possible on a computer that would be impossible or at least difficult to manage with a real brush.   When you select the brush tool and then look at the options, you will find shapes being offered as well as choices that are similar to how wet the brush is and how thin the paint is with a real brush.   Further more, there are choices as to how often the shape/image is applied - instead of just squishing the paint on, it is like you shaped a set of bristles and then stabbed the painting surface every 1/16th inch or 1/8 or every t/10th of a second as you moved faster or slower - really impractical with a real brush but part of the selections on a computer drawing  

  Sometimes having a shape lets you get into spaces or modify areas that would be very difficult if just round or flat brushes were allowed.