In the 1928 essay “a room of one’s own”, it refers to the space a woman needs to write fiction.
Specifically, Woolf says that a woman needs two things to be able to write: “money and a room of her own.”
The essay was drawn from two papers Woolf gave at the Arts Society at Newnham and the Odtaa at Girton in 1928 on the subject of women and fiction.