A Web host provides you with the resources to make your site available over the Internet. Unless you have your own Web server in the back room (and hopefully a competent staff to manage it), you’ll need an account with an organization that provides this service.
To use a vastly oversimplified metaphor, think of the Internet as a giant network of file cabinets. When someone wants to view a Web site, they electronically request the folder that holds the Web pages that make up the site they want to view, and their browser displays it for them. A Web host, then, is sort of like a big electronic file cabinet that holds the folder that holds your Web pages, which make up your Web site.
There are various levels of Web hosting services. Some hosts, like Google Sites, WordPress, and Yahoo!, will host your site for free. However, the “cost” of this kind of hosting usually is that the hosting provider will display ads on your site. These ads provide the income that pays for your free hosting. You may or may not have any control over what ads are shown — you could end up displaying a direct competitor’s ad right next to your own content! Another drawback of “free” sites is that your URL or Web address will usually contain undesirable elements like the name of the host in some form, such as www.yoursite.big-host-sites.com. This is not acceptable for most business Web sites. You need a hosting account that will work with your own domain name, www.yoursite.com, and for this you will usually have to pay.
The next level is often called “shared hosting.” This means you purchase space from a Web host which physically stores your Web pages on a server that is shared with other sites. Sometimes there are concerns about security and resources with shared hosting, especially if you are handling sensitive data or have a large amount of traffic, but shared hosting can be a good solution for most small organizations.
Reseller hosting is a type of shared hosting. This means that someone has purchased an entire server from a larger Web hosting company and resells space on that server to defray the cost. For example, a web designer or IT consultant might want control of their own server to host their own site, write and test software applications, etc., but they might also sell some of that space to their clients who need hosting space.
You can purchase shared hosting through many national and local companies, some of whom provide extras like shopping carts, email addresses, advertising credits, or 24-hour phone support as part of their packages. See the links below for more information.
For larger organizations, it is possible to host your site on its own server, but this level of service is beyond the budget and needs of most small businesses and nonprofit organizations. However, you can read more about the different types of web hosting here.
A quick Internet search will help you find links to companies that provide hosting services. I don’t endorse any particular hosting company and will be happy to upload your pages to any host of your choosing.