BODY SIZE - The size of type point is found by measuring from the highest ascender line to the lowest descender line. These lines are measured to the highest and lowest point of the text, including the white space left above and below smaller letters.
This is the type alignment known as justified and unjustified setting. justified—text is aligned along the left margin, and letter- and word-spacing is adjusted so that the text falls flush with both margins
Justified setting-that is, type that is flush on both the left and right margins. Used well, justified type can look clean and classy. When it’s carelessly set, however, justified type can make your text look distorted and hard to read.