Web Hosting
Knowledge of website hosting is essential if you plan to make your website available for the world to see.
Learning HTML/CSS would be a benefit when you are finally hosted!
If you already have a hosting provider that's great! But, if you don't, you'll need to start looking for one.
Whether you already have a web host or you're just beginning, you should know at least a little bit about the following hosting concepts:
The differences between shared hosting, dedicated servers, and managed hosting
How to choose a good web hosting provider
Domain names (i.e. yourwebsite.com)
FTP - for uploading your website to the hosting provider
Availability - how to monitor your web site's availability
Technical support - what to expect from a hosting provider
It can be very difficult for a beginner to find information about this. Furthermore, there are many experienced web developers who don't know exactly what it is their web host does.
Courtesy to quackit.com