The first time drones without pilots were used in 1973 in the Vietnam War when a airplane went down and no-one perished on account of this new technology. Drones are unmanned plane remotely controlled using software-controlled flight designs. Technically, They're aerial robots flown autonomously using a GPS and onboard sensors. https://randomfactsinhindi42974.fare-blog.com/28267657/the-basic-principles-of-portable-generator-engine-oil-type