From television to magazines to Web sites, all media have interfaces.

Conceptually, an interface is where your mind meets the medium, where the thing - the magazine, the TV set, whatever - tells you how to navigate it, how to find what you want to find, or how to do what you want to do.

A magazine's front cover and table of contents (which gives detailed story information and page numbers) are crucial interface elements. All you need to know to "interact" with a TV is that there are "channels" that can be changed by pushing buttons - or (way back when) by turning a dial.

Like me, you probably don't think about the interfaces of most media because you learned to use them when you were a kid. But the Web probably wasn't around when you were a kid, and Web interfaces are a lot less intuitive than TV or magazine interfaces. Still, like all media, the Web has a system of interface conventions that let you get to the information you want, and get past what you don't.

This time, we'll look at the basic interface elements that you're apt to see on the Web. These include hyperlinks, ad banners, homepages, site navigation, frames, search fields, and online forms.

Since you made it to this article, presumably you have some experience with hyperlinks (or simply "links"), which get you from Web page to Web page. Sometimes links take the form of buttons, sometimes they look like pictures, sometimes they are words that are a different color from the rest of the text and are usually underlined. (The word "hyperlinks" in the previous sentence is a link.) In the old days, all links were blue, but now Web authors can make them any color they please, which can be confusing.

The way to know for sure what is and what is not a link is by using your mouse: Move the cursor over a picture or a word; if it's a link, it will change from an arrow into a little hand with a finger extended. This indicates that you can click on it to go somewhere else.

If you've already been to the site where a link is going, the hyperlink will usually change color. For example, notice the color of this link before you click on it. Then, after clicking on it and coming back to this page (by clicking the Back button in your browser), notice that the link has a new color.

As you move around the Web, you'll want to click on some things and not others. It's up to you to decide, but it helps to have some idea where a link will take you before you click on it. Luckily, a few clues can help:

See the rectangular pictures at the top of this page? They're ads. Many commercial Web sites are supported by advertising and most run ads of the same standard size (called a "banner"), which makes ads easy to spot.

Another strategy for navigating hyperlinks is to move the cursor over a link without clicking. In most browsers, the URL (the location of the page) will be displayed in a status bar, usually at the bottom of the browser window. In many cases you can get a good idea of where a link will take you simply by looking at the URL.

Some Web sites try to make it clear - by what word or words they choose to link from - where you'll be taken if you click. So, in the phrase "crazy hippie," if the link is on crazy, it will likely mean something different than if the link is on hippie, which will mean something different still than if the link is on crazy hippie. Click on the three different links in this paragraph to see what I mean.

Most media that you use are more rigidly structured than Web sites. Time-based media like television and radio move linearly from start to finish, leaving you no choice of where to go. Newspapers aren't strictly linear, but because you can hold them in your hands you always know whether you're at the beginning or middle or end. You can start on page one with the hard news and move forward, or you can start on the fluff news in the entertainment section and move backward.

Web sites, on the other hand, branch off in many directions. People refer to "Web surfing," but it's more helpful to imagine yourself as a cheeky monkey climbing around a tree. You start at the trunk of the tree, then shimmy up and climb along a branch out to the end, where you find tasty leaves and nuts. The main page, the trunk, of a Web site is usually called the homepage or frontdoor. As you move from the homepage deeper into a Web site, the information tends to get more specific, branching out from general categories or sections to specific articles and features. And when you get tired of sitting on one branch, you can simply swing over to another one by clicking on a link.

Due to the branching nature of Web sites, each page usually contains navigational elements. Look at the left side of this page, for example, where a rectangular navigational bar lists other sections of Webmonkey Guides that you can visit. On the right is another box that lists other articles you can read, as well as related glossary terms.

It would be great if a Web site were like a magazine, so that you could pick it up and thumb through it, but it's not. And even if you could physically flip through a Web site, it'd be like thumbing through a whole stack of Sears catalogs because, unlike print media, a Web site can provide access to all the material it has ever published.

A few common interface elements will help you navigate most sites. First is the Back button on your browser, which will take you back to the last page you were on. Each time you click the Back button, you'll move one page farther back.

Beyond your browser's navigation buttons, you're at the mercy of whoever designed the Web page you're on. Luckily there are usually links on the page that will take you up the branching hierarchy of the site. Look for links like "back" or "home" or "top," which will take you back toward the "trunk" of the tree. Most sites will also usually include the logo or the name of the site that, if clicked, should take you to the site's frontdoor. And if you get completely lost, you can always type a URL (such as http://www.hotwired.com/webmonkey/guides) into your browser's address or location box.

Oh, there's one other part of the navigational system we should talk about: frames. Some sites use them pretty wisely, other sites don't use them at all, and lots of sites use them excessively.

What frames enable you to do is to keep some things constantly visible in your browser window while other things can change. Many sites will put an ad in a frame so you can't scroll away from it (advertisers like that). This works because each frame in a frameset has its own scrollbars which work independently from each other. Frames can be divided horizontally (splitting the page into a top and bottom) or vertically (splitting the page into two sides).

A lot of sites don't use frames because pages with frames are slower to download, and it's more complicated to make a page that also works on older browsers. Besides ads, frames are often used to hold navigational elements like a site directory that is useful if it stays on the screen and never scrolls away. Frames sound like a good idea, but they're often not used very well.