O-z.nl is an online information platform and part of Veel.nl, offering answers to more than 50,000 frequently asked questions. Visitors can browse a wide range of categories to find clear explanations on topics including general knowledge, public figures, professions, animals, entertainment, food, finance, health, lifestyle, travel, technology, sport, transport, science and home life. The site is organized around searchable questions and answers, making it a resource for people looking for practical information across many areas of everyday life.

Alongside its question-and-answer library, O-z.nl publishes recent blog articles. These cover subjects such as office facilities, staffing and administration in the security industry, and choosing eclipse glasses, as well as consumer questions about where to buy them. The site also features articles about well-known people and other topical subjects. O-z.nl is operated by Maddeco vof, based in Maartensdijk, and provides a contact email for questions or comments. Its broad selection of categories and regularly featured articles positions it as a general-interest destination for quick, accessible explanations.