Your website has to be hosted in order for your content to be seen and accessed by anyone. You pay yearly for this and there are many different options out there!

When you are looking at hosting services you need one that has as much up time as possible (this means that it is available/viewable as much as possible 100% would be perfect but can't be guaranteed by anyone and if they do steer clear!)
Your hosting company also needs to have a fast server so that it can deliver the pages fast.

Many servers have a very large load with 1000's of websites on each one, let me explain how this works,
imagine you have 1 door to a shopping mall with thousands of shops all with sales on
the mall is opened, now imagine that you have 1000's of people all trying to get through ONE DOOR at the SAME TIME!
Congested right?

Our servers are kept up to date, this means fast memory, hard drives etc all to help produce the fastest speeds for page viewing then we keep only a certain amount of websites on each of our servers to reduce the demand or load on the server, in the above example that is like adding in many doors so the customers can easily and calmly get through the doors to their specials!