Ganesh Chaturthi celebrates the birthday of the Lord of wisdom and prosperity – Lord Ganesha. This puja is the festival version of the Ganesh Vrata—also known by the name of Siddhi-Vinayaka Vratam—is done as a special vrata for the attainment of some particular end in view, usually for clearing oneself of false and unjust accusations and charges, recovering lost objects, regaining lost status, and removal of obstacles in an enterprise. It is to be performed on the fourth day of the dark fortnight. It consists of elaborate worship of Lord Ganesha with Shodashopachara (a 16 step worship) and various offerings, after appropriate Sankalpa (desire).
The divine sage Narada prescribed this vrata to Sri Krishna who wished to wipe off the dishonour of the charge of stealing the Syamantaka gem. Much later, Krishna instructed Yudhishthira to perform this vrata at the time of the Mahabharata war. This vrata was done by Devas to obtain Ambrosia on the eve of churning the ocean, by Damayanti to find her lost husband, by Lord Rama to get back Sita, by Indra to defeat Vritra Asura, by Bhagiratha to get down the celestial Ganges, by Draupadi and by Samba to get cured of incurable disease.
If you perform this vrata, you must arise early and bathe to cleanse the body. Vrata is observed from dawn to moonrise. The sankanthara vrata has to be done without eating food and water. The vrata has to be broken at the moonrise time after doing puja to the Lord Ganesha. For those who cannot observe the fast owing to a medical condition or other compelling reasons, you can drink water but not too often. Drinking too much fluid (often, even water), eating tobacco, or betel nuts, or betel leaves, or any other activity is prohibited and will break the fast. One cannot smoke or consume alcohol or eat the meat of any kind during vrata or after breaking the fast, and the fast cannot be broken with meat products.
While the other, you can keep a less stringent Phalahar vrata (fast). Devotees are allowed to consume tea, water, juices, and coffee etc. You are permitted to have sweets like Til ka Ladoo (sesame sweetmeat), gajak and rewari (sweets made of sesame and jaggery). You are also allowed to eat fruits.
After the ritualistic cleaning (bath) in the morning. One should either perform a small puja at their home or visit the nearest temple to offer prayers to the deity. White flower(for success and fame), Arugam grass (good luck, prosperity, and children), vermilion (sindoor brings good fortune), light incense sticks (for fame) and laddoo (sweets helps fulfill desires). In the temples, special puja will be conducted with the chanting of sacred hymns and mantras. This creates a perfect festive mood for the devotees, who flock the religious place to invoke Lord Ganesha and seek his blessings. The devotees can offer prasad to the deity. Sweets specially modaks are prepared by women and presented as offering to the lord and then shared as prasad among all devotees.
The fast of Ganesh Chaturthi ends after offering prayers to Lord Ganesh the next morning in a temple or at home. In order to stay concentrated, the devotees chant mantras invoking Lord Ganesha and sing bhajans in his praise.
It is believed that if one observes fast on Ganesha Chaturthi with sincerity, he/she would be blessed with health, wealth, and prosperity.