A web hosting is a service offered by web hosting provider by which you can make your website available on the internet. A web hosting provider provides space in their web server to store website data. The server space comes with a nominal amount that client need to pay to the service provider.
Server uptime means how functional and productive your web server can be. The functionality of web server defines the functionality of your website. More server uptime means a more functional website.
A datacenter is a place where many web servers are kept. A datacenter is specially made keeping the safety and security of a web server. Staff takes care of temperature, humidity, cleanliness, lighting of a datacenter and maintains server friendly environment.
A web server is the most important element when it comes to host a website on the internet. A web server provides space to a website to store its important data so that it can be accessed by the intent users on the internet.