The host may also provide an interface or control panel for managing the Web server and installing scripts, as well as other modules and service applications like e-mail. A web server that does not use a control panel for managing the hosting account, is often referred to as a "headless" server. Some hosts specialize in certain software or services (e.g. e-commerce, blogs, etc.).
Word of mouth only gets you so far in this internet-centric age. These days, people discover new businesses—even local business—via Bing, Google, and Yahoo, search engines that make it incredibly simple to find companies' products, operational hours, and prices. If your business doesn't appear in the search results, especially on the first page, it'll be difficult for potential clients and customers to find you. In other words, no website, no money. Of course, web hosting isn't just for businesses. You may want to host a personal website or blog, too. Either way, the services here have you covered.
Many services offer so-called unlimited or unmetered service for whatever amount of bandwidth, disk storage and sites you use. It's important to understand that most terms of service actually do limit the definition of "unlimited" to what's considered reasonable use. The bottom line is simple: if you're building a pretty basic website, unlimited means you don't need to worry. But if you're trying to do something excessive (or illegal, immoral or fattening), the fine print in the terms of service will trigger, and you'll either be asked to spend more or go elsewhere.