A darknet market is a type of website where people can buy and sell things that are either illegal or hard to find. It's called a "darknet" because it's not accessible by regular search engines like Google or Bing - you have to use special software to access it. Many of the items sold on darknet markets are illegal or illicit, such as drugs, stolen credit card numbers, or other illegal items. It's much harder for law enforcement to track what happens on these sites than it is on regular internet sites.