Legibility is the degree to which individual characters in text are understandable or recognizable based on appearance. "The legibility of a typeface is related to the characteristics inherent in its design … which relate to the ability to distinguish one letter from the other." Legibility includes factors such as "x-height, character shapes, stroke contrast, the size of its counters, serifs or lack thereof, and weight."Legibility is different from readability, which refers to entire words, sentences, and paragraphs. Readability is influenced, among other factors, by font choice, point size, kerning, tracking, line length, leading, and justification.In practical application some attributes cross over and affect both.