Diction is the choice of words writers use to communicate their ideas. They base their choice of diction on the content, type or piece of writing, and audience. When writers are making this decision, they focus on the connotation of the words rather than the denotation. Connotation concerns the feeling the word invokes, whereas denotation is the word's dictionary definition.

Essentially, by incorporating certain types of diction, writers accomplish the following:

Tone: Different types of writing can warrant different tones. Diction allows writers to develop a tone appropriate for the subject matter (i.e., fiction vs. nonfiction). A short story, novel, or poem would contain different diction and writing style than a scientific report or persuasive essay.

Setting: In fictional works, a writer's choice of diction can help identify the text's setting through the use of words native to the time and place in which the story takes place. By using careful diction, authors can create more authentic work.

Characterization: The different words characters use in a literary work can help the author develop their identities. Diction can help identify characters’ education, age, profession, etc., making them more realistic.

Formal: Formal diction uses sophisticated language that follows grammar rules and avoids personal pronouns and contractions. Professional texts contain formal diction, such as research reports, legal documents, and scientific studies.

Informal: Informal diction consists of everyday language. It uses slang words, contractions, and personal pronouns. People use this type of diction in casual conversations and when communicating with friends and family.

Colloquial: Colloquial diction refers to words or expressions spoken in a specific time and place by a wide range of people. It incorporates informal diction and regional expressions (e.g., soda vs. pop).

Slang: Slang is extremely informal and is often restricted to a certain group of people or professions. These words and phrases are often generational, and words are often replaced as generations shift (e.g., groovy vs. cool). While similar to colloquial language, slang is not as widespread and is not solely dictated by region.

Concrete: Concrete diction is when a writer uses the literal definition (denotation). These words are not open to interpretation and do not create an emotional response.

Poetic: Poetic diction involves the type of language used in poetry that differs from typical conversational diction. These words create the rhythm and rhyme incorporated into poetic verse.

Jargon: Jargon is a language dedicated to a specific field of study, which can include a profession, trade, or hobby.