Kalki is the tenth and last avatar of Lord Vishnu, who is yet to come in the future. He will appear at the end of Kali Yuga, a time when people forget truth, kindness, and goodness.
Kalki will be born in a village called Shambhala. He will grow up to be a brave and wise warrior, riding a white horse named Devadatta and carrying a sword that shines like the sun. With his strength, he will destroy evil rulers and protect good people.
After defeating the demon Kali, Kalki will bring back peace, honesty, and happiness in the world. This will begin a new age called Satya Yuga, the golden age of truth.