A chatra, chattra or chhatra (Sinhala, Sanskrit छत्र, chatra, "umbrella", "parasol") is an ashta mangala one of the eight good omen symbols of Indian religions such as Hinduism, Buddhism, Jainism or Sikhism.
For the digambara branch of Jainism, it is an umbrella, a small parasol to protect from the bad things that can come from the sky. It is a shelter, a protection against harmful things that can affect you.
In other religions such as Hinduism and Buddhism, the umbrella symbol is also used. In Sikhism, above the altar or its holy book, the Guru Granth Sahib which is displayed under a canopy called chanani that serves as a protection against dangers or bad vibrations that may come from the sky. It is also a mark of respect.
For Hindu mythology, it is the emblem of Varuna, also considered as an expression of power, of royalty. Several deities are represented with chatra, such as Revanta, Surya and Vishnu (in his avatar of Vamana).
The chatra is among the symbols that approach universality within the numerous octavalent sets of ashtamangala.
In the iconography of the dharmic tradition, in the thangkas of traditional Tibetan medicine and in Ayurvedic diagrams, the chatra is uniformly represented as Sahasrara.
Also the chatra shares a similar symbolic value to the baldachin, with reference to the image of Vishvakarman.
The chatra can symbolize power, prestige or the sacredness of a person, object or place. But it is also a characteristic element of Buddhist architecture, a kind of parasol that tops in variable number and size the upper part of the stupa, above the dome and the harmika.
The verticality of the set of chatras is identified with the axis of the world and reinforces the idea that what is below is very important, as one of the centers of the universe to which it gives spiritual protection.