Which term describes informal vocabulary composed of invented words or expressions used by specific groups?

The term that describes informal vocabulary composed of invented words or expressions used by specific groups is slang. Slang refers to a type of casual and often playful language that may differ substantially from standard language conventions. It typically evolves rapidly and can vary significantly between different cultures, regions, and social groups. Slang often reflects the values, interests, and experiences of the group using it, making it a dynamic form of communication that can create a sense of identity among its speakers.

In contrast, jargon refers to specialized language associated with particular professions or fields, such as technical terms used in medicine or law. While jargon is often used within specific professions to communicate complex ideas succinctly, it is not characterized by the informal and inventive quality of slang. Proofreading and editing relate to the processes of reviewing and correcting written content but do not involve the creation of informal vocabulary.