Cucurbiturils are a class of synthetic molecules shaped like hollow, barrel-like structures. They are made from sugar molecules called glycouril and can encapsulate smaller guest molecules within their cavity. This unique property makes them useful in various fields, including drug delivery and molecular recognition. These compounds can selectively bind to different substances, allowing for targeted applications in chemistry and biology. Researchers are exploring their potential in creating new materials and improving the efficiency of chemical reactions, making cucurbiturils an exciting area of study in supramolecular chemistry.