Often, shared hosting boasts unlimited disk space, unlimited bandwidth, unlimited domains, and basically unlimited everything. While they claim to offer unlimited resources, you’re required to be fully compliant with your hosting company’s Terms of Service and only utilize disk space and bandwidth in the normal operation of a personal or small business website.
When it comes to server operating systems, Linux is typically the default option. Still, some services offer a choice of Linux or Windows hosting. If you have specific server-side applications that require Windows, such as SQL Server or a custom application written in .NET, then you need to make sure your web host has Windows hosting. But don't let the idea of a Linux host intimidate you. Nowadays, most web hosts offer a graphical interface or a control panel to simplify server administration and website management. Instead of typing at the command line, you'll click easily identifiable icons.
A domain name is a website address made of a website name, followed by a dot, then an extension like .com (fitsmallbusiness.com, for example). You can receive a free domain by buying web hosting packages that include them or via domain name registrars offering little-known extensions like .tk. Paid domains offer extensions that lends to greater business credibility like .com or .net domains.