A hololab is a term for a small laboratory equipped with a holographic matrix, enabling its user to create simulations and run other scientific and engineering tests. Generally speaking, a hololab is smaller than a holodeck, allowing them to be set up on smaller vessels. The USS da Vinci had one hololab, which was reserved for official use only. (SCE eBook: Here There Be Monsters) However, this restriction did not prevent some crew members from using it recreationally. (CoE eBook: Remembrance of Things Past, Book I)