Web hosting is a type of Internet hosting service that allows individuals, companies or organizations to make their website accessible via the World Wide Web.
In general, most websites are intended to be viewed by anyone on the Internet, at any time. If you want anyone on the Internet to be able to view your website at any time, you need to make sure your website is running on a computer which is connected to the Internet 24 hours per day, 7 days per week (24/7).
You probably thought that ‘I built my website on my computer and I can visit the website well, then why I need a web hosting?’ The thing is that your computer is not public to the Internet, when others want to visit the website on your computer through Internet, they will need to ask your permission to do that. And also you cannot keep your computer running around the clock.
After you bought a web hosting service from a web host (provider of web hosting service), they will setup a web hosting account for you and provide you a control panel and some other information to manage your web hosting. You can then upload your website to your web hosting server with FTP information provided by the web host to make it accessible to anyone at anytime on the Internet.