Deixis refers to linguistic expressions that can only be interpreted based on contextual information about who is speaking, where, and when. Deixis includes pronouns like I, you, and demonstratives like this and that. The meaning of deictic expressions depends on the deictic center, which is the speaker's point of view in terms of person, place, and time. There are different types of deixis, including person deixis referring to speakers and addressees, place deixis indicating locations, and time deixis referring to moments in time. Deixis is a fundamental aspect of language that allows speakers to anchor meanings to the immediate context of an utterance.