One day Maa Parvati went to the bath, In order that no one disturbs her during her bathing ritual at the Palace without her permission she molded a young boy from her Chandan paste and named him Ganesh. Maa Parvati ordered Ganesh that no one should be allowed inside the house until she permits them to, or till the time her ritual is over.
When Lord Shiva returned, he saw a Boy child standing guard at the door. The repeated attempts of Lord Shiva and Lord Nandi to get inside the palace failed as they were stopped by Ganesha. Lord Shiva was angered by this act, seeing Lord Shiva angry, Nandi the riding bull of Lord Shiva challenged Lord Ganesha for a duel, but in the duel, Nandi had to face defeat at the hands of Lord Ganesha. Nandi's defeat and the failed repeated attempts made Lord Shiva further angrier, and in an act of his rage, he slew Lord Ganesha's head from his body.
Now when Mata Parvati came back she became very sad and started crying profusely. On learning his mistake that Lord Ganesh is none other than his own son, Lord Shiva tried to put his point forth and explain his action. If a child is hurt the mother, is the one who would go against everyone to get the best treatment for her child. such as the case with Maa Parvati, unwilling to listen to Lord Shiva, She was so angry that the mother of the universe, was on the verge of ending the universe.
To calm her down at this point of Timelord Shiva ordered his shivgan to get the head of the first being they see but the head should be given to them by the being's consent. the head that they got willingly was of a dying elephant. They got the head of the elephant and a fixed it on the lifeless body of Lord Ganesha, and with his powers, Lord Shiva resurrected Lord Ganesha back to life. and therefore named Ganesha as Ganpati and all the other gods gave him a boon that whatever new work they will do, they first do the Puja of Lord Ganesha. Lord Ganesha is the removal of obstacles.
People worship Lord Ganesha for prosperity, happiness, and peace in their families. He is the son of Lord Shiva and Goddess Parvati. If you wish to perform the Lord Ganesha Puja by our well-versed purohits.