A typographer is a person who designs the form and arrangement of type to make the written word more legible and aesthetically pleasing. Such a person might design a font, or define the point size, kerning, and other characteristics of a typeface.
Typography vs. type design
Typography is performed by many individuals in many different fields, including graphic and web designers, clerical works, and book artists. However, designing the look of type is not always considered a part of typography. That is to say, most typographers do not create typefaces and some of those who design type do not consider themselves typographers.