A fully qualified domain name (FQDN) is a domain name that is completely specified with all labels in the hierarchy of the DNS, having no parts omitted. Labels in the Domain Name System are case-insensitive, and may therefore be written in any desired capitalization method, but most commonly domain names are written in lowercase in technical contexts.
Linux is the most commonly-used operating system for web hosting in the world, and Linux servers are a popular choice for many websites and applications. It is the industry-standard operating system, and in fact, one of the most popular groups of applications used to back websites is commonly referred to as LAMP, which stands for Linux, Apache (a web server), MySQL (a database), and PHP.
The first step in building your online presence is finding a web host, the company that will store your website's files on its servers and deliver them to your readers' and customers' browsers. Web hosting services offer varying amounts of monthly data transfers, storage, email, and other features. Even how you pay (month-to-month payments vs. annual payments) can be radically different, too, so taking the time to plot exactly what your company needs for online success is essential. Many of these companies also offer reseller hosting services, which let you go into business for yourself, offering hosting to your own customers without requiring you to spin up your own servers.