👉 Cookie fluid, often used in web development and machine learning contexts, is a type of probabilistic data structure designed to efficiently store and retrieve sparse data, such as user preferences or session information. It works by associating each possible value with a set of "slots" or "buckets," where each slot can hold multiple entries. When a user interacts with a system, the cookie fluid updates these slots based on the interaction, typically by assigning a probability to each slot that reflects the likelihood of the user's choice. This allows for quick and memory-efficient updates and queries, making it particularly useful in scenarios where data is sparse and updates are frequent, such as in recommendation systems or session tracking.