The festival nurtures a rich heritage of legendary traditions, some rooted back to the ages of the great epics. In the Hindu tradition the Rakshaa has indeed assumed all aspects of protection of the forces of righteousness from the forces of evil.
According to the Mahabharata, Yudhishthira, the eldest of the Pancha Pandyava (the five brothers belonging to the family of king Pandu), asked Sri Krishna, an incarnation of lord Vishnu, how best he could guard himself against impending evils and catastrophes in the coming year. Krishna advised him to observe the Rakshaa Ceremony. He also narrated an old incident to show how potent the Rakshaa is. It went like this.
Once, Indra, the king of heaven was confronted by the demon king - the Daitya-raaja - in a long-drawn battle. At one stage, the Daitya-raaja got better of Indra and drove him into wilderness. Indra, humbled and crest-fallen, sought the advice of Brihaspati, the Guru of Gods. The Guru told him to bide his time, prepare himself and then take on the mighty demon. He also indicated that the auspicious moment for sallying forth was the Shraavana Poornima. On that day, Shachee Devi, the wife of Indra, accompanied by Brihaspati tied Raakhi around Indra's right-wrist. Indra then advanced against the Daitya-raaja, vanquished him and reestablished his sovereignty.
This is how Raksha Bandhan came into being in the ages of old Hindu mythology and has transcended into the modern ages acquiring more of new and modified customs with itself.

A rakhi is not mere a string but an unbreakable knot of never dying relationship between a brother and sister. This simple thread create an eternal bond of love between siblings. The festival is also associated with love, joyfulness, rituals, sentiments and pray to almighty God.Raksha Bandhan falls in the month of Shravana, which is the month when monsoon season is coming to an end and the weather is pleasant and beautiful. This festival is also known as 'Rakhi Purnima' across the globe. This day is devoted to the Rain God Indra and the Sea God Varuna.

This auspicious day begins with the rakhi tying celebration. Sisters tie rakhi on the wrist of brothers and pray for their well being. In return, brother give pledge to protect her. Rakhi festival is all about raksha or protection of our dear ones also. Each ritual that is followed on this day has a significance of its own. The sisters seek love from their brothers, the brothers seek courage and endurance. People worship the Gods of water, the basis of life. Rakhi is all about living life in a harmonious manner along with the celebrations of brotherhood and love.