Vrata is a vow.
Every Vrata has its story (Katha), the narrations are called Vrata Katha.
Vows are depending on the day of the week, the season, the position of the planets, fasting, pilgrimages, donations, keeping silent (mauna). They are always combined with a wish.
The Vrata is followed by the Utsava, the celebration of joy as a reward for effort.
Find a collection of Vrata Katha here