"They" is a pronoun used in the English language to refer to a group of people or things. It can also be used as a singular pronoun to refer to an individual whose gender is unknown or to someone who identifies as non-binary. This usage promotes inclusivity and respects individual identity. In grammar, "they" serves as a third-person plural pronoun, replacing nouns to avoid repetition. For example, instead of saying "John and Mary went to the store," one might say, "They went to the store." This makes sentences clearer and more concise while maintaining the same meaning.