A transition or linking word is a word or phrase that shows the relationship between paragraphs or sections of a text or speech.[1] Transitions provide greater cohesion by making it more explicit or signaling how ideas relate to one another.[1] Transitions are, in fact, "bridges" that "carry a reader from section to section".[1] Transitions guide a reader/listener through steps of logic, increments of time, or through physical space. Transitions "connect words and ideas so that [...] readers don't have to do the mental work for [themselves]."[2]
Transitions reveal the internal structure of an author's reasoning. While they are used primarily for rhetoric, they are also used in a strictly grammatical sense for structural composition, reasoning, and comprehension. Indeed, they are an essential part of any language.
In simple terms, a transition word demonstrates the relationship between two portions of a text or spoken language. By using these words, people can better build a sentence and convey what they are trying to say in a more concise manner.[3]