Refers to the distance between the baselines of successive lines of type. The term originated in the days of hand-typesetting, when thin strips of lead were inserted into the forms to increase the vertical distance between lines of type. The term is still used by 'professionals' and in modern page layout software.
The process of adjusting the spacing between characters in a proportional font, to achieve a visually pleasing result. In a well-kerned font, the two-dimensional blank spaces between each pair of characters all have similar area.
Also called "letterspacing," refers to the amount of space between a group of letters to affect density in a line or block of text. Often confused with kerning.
are those words or short phrases at the end or beginning of paragraphs that are left to sit alone at the top or bottom of a column — separated from the rest of the paragraph.