Rings and its meaning....
Promise Ring
A promise ring is given to a romantic partner to signify a promise to be committed in a monogamous relationship, maybe in which a young couple pledge their love for one another. The gift of the ring indicates that serious courting is under-way. It can be given as a symbol that a couple does not feel that it is an appropriate time to consider engagement or marriage but are serious about each other and their relationship.
A promise ring can be worn on any finger on the left or right hand, although ring fingers are far preferred. Most often it is the left ring finger, but due to engagement confusion, the right ring finger is finding acceptance in today's world.

Engagement Ring
An engagement ring is a ring worn by a woman on her left-hand ring finger indicating her engagement to be married. It is customary for the ring to be worn on the right-hand ring finger in countries like Germany, or in Eastern Europe. By modern convention, the ring is usually presented as a betrothal gift by a man to his prospective bride while or directly after she accepts his marriage proposal. It represents a formal agreement to future marriage.
Wedding rings
A wedding ring or wedding band consists of a precious metal ring, in certain countries (UK, USA, Brazil) worn on the base of the left ring finger – the fourth finger (counting from the thumb) of the left hand. In most other parts of the world, it is worn on the right ring finger. Such a ring symbolizes marriage: a spouse wears it to indicate a marital commitment to fidelity.
