Shared server
Your website shares a Web server with other customers. If your site experiences heavy traffic, or if one of the other sites on the server does, your website could crash.
Major vendors: GoDaddy.com, 1&1 Internet, Yahoo Small Business, DreamHost
Price: From $4 to $25 a month
Grid server
Your website is hosted on a grid of servers. If your site experiences heavy traffic, other servers will pick up the load.
Major vendors: Media Temple, Mosso, 3Tera, Layered Technologies
Price: From $20 a month, with some services charging extra for resources used during traffic spikes
Virtual private server
Your website uses a large slice of a dedicated server. If other sites on the server max out, your site should run normally.
Major vendors: Spry VPS Hosting, Verio, Media Temple, Web.com, GoDaddy.com
Price: From about $35 a month
Dedicated server
Your website is hosted on its own server. This option offers the most capacity for a fixed price, but a sudden flood of millions of visitors could still overwhelm the server.
Major vendors: Rackspace, The Planet.com, SoftLayer, FastServers.net
Price: From $75 to $1,000 or more per server per month, depending on the capacity required. Some providers also charge setup fees.