User stories are short, simple descriptions of a feature or functionality from a user's perspective. They are often used in agile development methodologies to help teams understand their users' needs and goals and define the requirements for a product.

User stories are written in the following format: "As a [type of user], I want [some goal] so that [some reason]." For example: "As a frequent traveler, I want to be able to search for flights by destination and date so that I can easily find the best flights for my trip." User stories are an important tool for product teams, as they help to ensure that the product is focused on the needs and goals of its users.