To create a website and make make your data and content accessible to your users, you need to store that data on the internet. That is where the term web-hosting comes into play.
WEB HOSTING :The business of providing storage space for websites to store their data, content and files on the web. The data is stored on advanced computers called servers. When you enter a website domain name in the address bar, it tells the computer on which server your content is stored and thus make it visible to users.
WEB HOSTS ( Web-hosting Companies) :
These are the companies which provides the web hosting services to the website owners to make their sites accessible on the web.
Lets make it more simple for you-
Your domain name acts as the address of your home whereas, web-hosting is the space inside your home where you have stored your things. Please note that, you need space to store your things .So, if someone wants to access your things, he/she has to reach your home (by using your address) for this.
This is the exact theory, when it comes to websites. You need a address (domain name) , space (web-hosting service ) to store you things which are the content, data and files related to your site.