Puterspace, also called the Matrix or a matrix in relation to the immediate area within Puterspace, was a form of virtual reality prevalent in the Earth Empire in the 26th century. It was accessed through a jack port installed on the back of the neck, or a wire crown for beginners, that linked the person with a puterspace deck.
The data was easy to get into by wandering around in it, and individuals were able to create their own places within a matrix or shape their virtual bodies to their desires. Additionally, different entities could be encountered, either created from the mind of an individual or already existing in the reality, such as the Trickster, Eros, and Death. Computer viruses could destroy a projection of a person in Puterspace, and subsequently kill their body in the real world.
The Travellers created the Land Under the Hills, or "the Dreaming," which was their own domain within Puterspace and held the Great Wheel. Rather than use drugs, they entered this reality to achieve higher states of consciousness, hold meetings, and see glimpses of the future. (PROSE: Prelude Love and War)
The Daleks could hack into Puterspace and create attack ships, but weren't very good at it and were vulnerable. Trap software developed by the Rutans could reshape a matrix around a person based on their worse memory or nightmare, trapping them there. Hoothi spheres were also able to enter Puterspace, but they may only have been able to do so with an infected person already inside. (PROSE: Love and War, AUDIO: Love and War)