It is perhaps most helpful to start by visualising the web as an iceberg. The section protruding above sea level is the Clearnet, the most accessible area of the web. The Clearnet is where anything freely accessible via a search engine such as Google is found and indexed.
Once below sea level, the largest section of the iceberg is the Deep Web. This part of the internet is where anything private, protected, and (more often than not) requiring authentication to access, is stored. To access this layer of the web, no special browser is necessary, but you will likely need the relevant passwords.
Finally, the bottom segment of the iceberg is the Dark Web. To gain access to this, having a normal web browser such as Chrome will not be enough. Special access tools are required. The Dark Web can be accessed using a special software - the most widely used one being the Tor (The Onion Router) browser. Two other examples are I2P and Freenet. Certain misconceptions have developed around the Dark Web. The Dark Web is commonly believed to be illegal to access. Whilst visiting it is outlawed in certain countries, and many of the services searched for on it are criminal, the Tor browser is legally accessible in the majority of countries around the world.
There are also misconceptions around who the typical Dark Web user is. Whilst many criminals do use it, there are contrasting sections of society who rely on it, such as journalists, whistleblowers and political activists who live in countries where #censorship and political oppression are common. The Dark Web can provide a #secure space for such people to communicate privately and anonymously.