Here is your short paragraph on Kashi:
Kashi is the earliest name of the city of Varanasi (Banaras) and is one of the seven sacred cities of India.
Originally it was the name of a kingdom of the Kashi, a people closely associated with Kosala and Videha in the late Vedic age.
Kashi seems to have been either the name of the first chieftain or simply that by which the tribe was known; but legend derives it from Kasa, a type of grass (Saccharum spontaneum) which carpeted the site chosen by its first ruler.
City’s proximity to the holy Ganges has served to enhance its religious importance and made it at various times a Brahminical, Buddhist, Jaina, Vaishnava, Saiva and Sakta place of pilgrimage. It was at Banaras that the Buddha first expounded his doctrine and where stands the great stupa commemorating the event.
The views of the Kasi religious authorities have always carried immense weight in the Hindu world. To Saivas, it is pre-eminently the city of Siva, the Lord of Kasi (Kasinatha).