The Internet we use daily to surf enjoy and entertain is just the tip of the iceberg. It constitutes for 4% of the total web or the internet daily being consumed.
The deep and the dark web was first made by the government to encrypt and hide sensitive information from civilians but gradually the dark web started to be used for illegal work like human trafficking, hiring Hitman, illegal pornography , selling drugs, selling illegal and private information of people. People also use the dark web for hacking.
The Deep web is used by the government officials to store encrypted information nowadays. Medical records, financial records, government reports and legal documents all are available on the deep web
The Dark web cannot be accessed by your normal search engine like Google, Bing and etc but needs special engines like Tor web,etc.