Word usage, otherwise known as diction, refers to a writer's choice of words and the manner in which he uses those words in a given piece of writing. The writer's choice of words varies significantly based on the type of writing in which he is engaging. A technical writer, for instance, tends to use words precisely and clearly, with the goal of transmitting information. His word usage typically differs from a poet, who often uses flowery and eloquent words to communicate intangible ideas, such as beauty and love. Word choice has a particularly important place in fiction, wherein works taking place in different regions and in different time periods often use significantly different words in order to develop some level of authenticity.
For most people, word usage simply means choosing the appropriate words to use in particular scenarios. This means understanding the meanings of words and how to use them in sentences. Many words have "connotations," or meanings beyond their technical definitions, however. Understanding both the technical meanings and the connotations of words is essential to proper word usage, as some words with perfectly acceptable definitions have unsavory or insulting connotations.
Word usage is a much more pressing issue for writers and speakers than it is for those in other professions. Writers generally must choose words that both clearly and specifically address the subjects they are discussing and that are clear and understandable to their audiences. When writing for a technically-proficient audience, for instance, a writer's word usage must generally demonstrate understanding of the jargon associated with the subject being discussed. When writing for a general audience, on the other hand, the writer must try to avoid jargon. For writing intended primarily to transmit information, the intended audience is generally the primary determinant of the writer's word choices.
Many writers and poets use language for artistic purposes and are, therefore, often less influenced by their audiences. Word usage, in such cases, takes on new and more complex dimensions, as the sound and rhythm of the words may be as important as the meanings. This is particularly true in poetry, much of which is governed by strict rules of rhythm and rhyme.
Artistic writers are not the only ones who are occasionally praised for their skilled word usage. Many writers whose primary purpose is to transmit information are well-regarded because of their ability to do so eloquently. Skilled use of words can make even purely technical writing seem almost artistic without detracting at all from its functionality.