Webmail provides an easy-to-use access point from any computer to read your mail privately and securely. With any standard web browser, you can easily type in "webmail.<whatever your domain is named>.com", and will be prompted for your username and password. For ZennMedia, for example, what you would type in is "webmail.zennmedia.com". A common interface used nowadays is known as Squirrel Mail, depicted - appropriately enough - by a squirrel as the mascot. There are other interfaces used by different server software, but overall, they tend to perform the exact same purpose. Unless you're the administrator of the site, you'd pretty much have little choice in choosing which interface will be used by the end user.