You need to get Hosting for your website as somewhere to store the files used by your site. A server is a computer, permanently running and connected to the internet that contains the files used by your website, and serves them up to a browser that requests them.
When choosing a Hosting company you usually get a choice of what type of Operating System the Server Uses, Microsoft Windows Server, or Linux. Although Microsoft may seem to be the obvious choice to use as it is what the majority of desktop computers run on, most web servers run on Unix or Linux based systems as they are generally more suited for this purpose.
There are also Cloud storage solutions that allow you to create a temporary cloud server for testing an application or to run a small piece of code online or to just serve static HTML files. These can also be used for hosting photos or even an entire website such as my Sugardrum website which uses Amazon S3 and Cloudfront to host the static HTML files.