Web hosting is a service which allows you to host a website online on a web server through which web browsers can access your website.
The web server is a type of computer that is in a data center that is online 24/7 and allows anyone to access your website with the domain.
Any website you've visited was hosting on a web server through web hosting services.
The types of web hosting include shared hosting, VPS Hosting, Cloud Hosting, dedicated hosting and mysql hosting.
Small websites typically use shared web hosting where they shared the serve with many other websites.
Larger websites use VPS, Cloud Hosting or dedicated hosting where they have more resources.
Dedicated Hosting means the website is the only one on the dedicated server unless the user is hosting multiple websites on the same server.