In linguistics, pragmatics and speech act theory, propositional content is defined as the meaning or message that is conveyed by a sentence or utterance. The content propositioned is the information that is being asserted or conveyed through language, its semantics and grammar, independent of the particular way in which it is expressed. Propositional content can be thought of as the underlying meaning of an utterance, stripped of its context, intonation, and other linguistic and paralinguistic features. It is the "naked" meaning of the utterance.
A proposition is a declarative statement that expresses a complete thought and can be evaluated as true or false. Propositional content can be thought of as the set of all propositions that can be expressed by a given sentence or utterance.
For example, the sentence "The cat is on the mat" has the propositional content that a cat is located on a mat, but not that you should go pet it. The sentence "It's raining outside" has the propositional content that precipitation is falling from the sky. However, meaning to say that it is raining outside, implying we shouldn't go out, is not part of the propositional content. The propositional content of a sentence is independent of the particular way or context in which it is expressed, so the same propositional content could be expressed in different ways. For example, the sentence "The mat is supporting the weight of the cat" has the same propositional content as "The cat is on the mat."
Propositional content is an important concept in pragmatics and speech act theory, as it helps to separate the meaning of an utterance from the particular words or phrases used to express it (like Illocutionary force and point). This is important because it allows us to understand the meaning of an utterance even if we don't know the specific words used, and it allows us to compare the meanings of different utterances even if they use different words and structures.