Vesta was introduced in Rome by King Numa Pompilius. She was a native Roman deity (some authors suggest received from the Sabin cults), presumably the daughter of Saturn and Opi (or Rea). However, the similarity with the cult of Greek Hestia is notable. Vesta too protected the familiar harmony and, extensively, the State.
Apollo and Neptune had asked for her in marriage, but she refused both, preferring to preserve her virginity, whose symbol was the perpetually lit fire in her temple, guarded by her priestesses, the Vestales. Every March 1 the fire was renewed. It burned until AD 394.
The Vestales were one of the few full time clergy positions in Roman religion. They had to observe absolute chastity for 30 years (they were also called the Vestal virgins). They could not show excessive care of their person, and they must not let the fire go out. If a Vestal broke her vow of chastity before the 30 years were up, she was condemned to be buried alive in the Campus Sceleris (camp of damned people); this is what probably happened to Rea Silvia.
The Vestales wore a tunica, a simple dress that they used for both the temple and everyday life (people in Rome usually dressed one way at home and another for the outdoors). In Italian, the vestaglia (dressing-gown) and the more generic veste (dress) are named after the clothes worn by the Vestales.
Vesta was celebrated at the Vestalia, June 7 to 15. On the first day of the festivities the penus Vestae (the sanctum sanctorum of her temple) was opened, for the only time during the year, for women to offer sacrifices in.