Theridion quadrilineatum is a species of spider commonly known as the four-lined cobweb spider. It is characterized by its small size, measuring around 4-6 mm in length. This spider is typically found in North America and Europe, where it constructs its intricate cobwebs in various habitats such as forests, gardens, and buildings. The species is known for its distinctive four dark lines on its abdomen, which give it its common name.