Before the dot-com crash, many Web pages featured pictures and text that the Web page administrators rarely updated. As Web editing software became more user-friendly, it became easier to make changes more often. Some companies continued to present information in a static, non-interactive way, but a few began to experiment with new ways of distributing information.
One new way was to use Web syndication formats like Really Simple Syndication (RSS). With RSS, users could subscribe to a Web page and receive updates whenever the administrator for that page made any changes. Some programmers designed applications that created RSS readers on PC or Mac desktops, which meant users could check on updates for their favorite Web sites without even opening a Web browser.
Another way of sharing information on the Web came as a surprise to many people: blogs. While people have created personal Web pages since the early days of the Web, the blog format is very different from the traditional personal Web page. For one thing, most blogs are organized chronologically, so it's possible for a reader to see the most recent entry, then go back into archives and follow the blog's progression from start to finish.
Blogs are a good way to get information out to readers fast. People read blogs, see things that interest them and write about it in their own blogs. Information begins to spread from one blogger to another. Marketing firms call this blog-to-blog method of transmitting information viral marketing. Many companies are looking into ways to use viral marketing to their advantage -- it's both powerful advertising and inexpensive because the targeted audience does most of the work for you.
Web pages like blogs rely on the use of permalinks. Permalinks are hypertext links that connect to a specific blog entry. Without permalinks, discussing blog entries would become a tedious process. All links would lead the user to the main blog page, which may have been updated since the link was first created. Permalinks allow users to anchor a pathway to a specific blog entry. If you see a particularly fascinating discussion on a blog, you can use a permalink to guide your friends there to read up on the subject.
Another key concept to Web 2.0 is the incorporation of non-computer devices into the Internet. Many cell phones and PDAs now have some level of Internet connectivity, and Apple's iTunes application integrates smoothly with iPods. O'Reilly cites the expansion of Internet services beyond computers as another example of how the Web is evolving.
In the next section, we'll look at how some members of the Web community dispute the need for the Web 2.0 term.