What is the difference between a guitar and an Indian slide guitar?

An Indian slide guitar grew from the Hawaiian lap-slide tradition: Brij Bhushan Kabra modified a Gibson Super 400 archtop guitar with a drone string and a high nut that lifts the strings off the fretboard. He played it seated and flat, with fingerpicks and a bar. He also added more chikari (high drone strings) and tarab (sympathetic strings).