Most people when they hear this word, they most likely think of the element lead itself, but for a graphic designer it is something completely different.
Leading is the space between lines of text or from baseline to baseline. The term leading came about because before the use of computers to make text, the people who ran presses would put little straight lines of lead in between lines of text so that they could not run on top of each other.
Most programs just do auto-leading. This mean that it sets the leading for you. Your average person also works with leading when they double space or single space a word document. They are doing this for a reason; readaiblity, space constrains, or any other number of reasons. Graphic designers also keep this in mind when they design. Words have to legible, readable, and convey the same meaning as the rest of the piece.

Tags: Graphic Design, line length, text, typography, What is
[...] a font and manipulate it using digital methods and terms such as typeface, point size, line length, leading, tracking and kerning. To put it even shorter, typography is the act of laying out the [...]