In order to be a real webmaster you need to have a domain and you should have a hosting space for your website which is called hosting.
Meaning of Domain
Domian name is the name of a website. Examples for domain names are such as google.com, yahoo.com, facebook.com etc. Domain names are needed for a website to be reached. You type the domain name into the adress bar of a browser and the browser takes you to the website. Ofcourse the process is not that simple, there are other intermediary mechanisms (DNS, server etc.) but for beginning purposes these are not obligatory to know.
Why do I need a hosting?
Hosting is the webspace you need to put your files those are related to your website. The webspace for websites are provided by servers on the web. Servers are similar to the disks on your PC or laptops. The only difference is that the information contained inside could be reached by online visitors. The files and folders within the servers are presented according to your permission.