Surface structure refers to the outward form or arrangement of a sentence in a language. It includes the specific words and grammatical rules used to convey meaning. For example, the surface structure of the sentence "The cat chased the mouse" consists of the particular words and their order. In linguistics, surface structure is contrasted with deep structure, which represents the underlying meaning or concept of a sentence. While surface structure focuses on how a sentence is expressed, deep structure deals with the ideas that the sentence communicates. Understanding both structures helps in analyzing language and its complexities.