A domain name is like a virtual address of the virtual land(web hosting). But Having only an address is equivalent to a piece of land without a home.
Web hosting can be simply described as a virtual land where you can build your own virtual house (Your Website) in the virtual world of internet.
These two things are necessary in order to build your virtual home -your website.
Domain name is a unique word, or a couple of words, usually associated with an IP address, that represents a special place on the Internet. You need a domain name because it gives a name of your place in the biggest society in the world – the World Wide Web.