安徽11选5遗漏前3 www.gwzsf.com The phrase Web 2.0 was created by O'Reilly Media to refer to a supposed second generation of network-centric services available on the internet that let people collaborate and share information online in a new way - such as social networking sites, wikis, communication tools and folksonomies. O'Reilly Media, in collaboration with MediaLive International, used the phrase as a title for a series of conferences and since then it has become a popular, if ill-defined and often criticized, buzzword amongst the technical and marketing communities.
With its allusion to the version numbers that commonly designate software upgrades, the phrase "Web 2.0" trendily hints at an improved form of the World Wide Web, and the term has appeared in occasional use for several years. The more explicit synonym "Participatory Web", emphasizing tools and platforms that enable the user to tag, blog, comment, modify, augment, select from, rank, and generally talk back to the contributions of other users and the general world community has increasingly seen use as an alternative phrase. Some commentators regard reputation-based public wikis, like Wikipedia, as pioneering examples of Web 2.0/Participatory Web technology.
O'Reilly Media and MediaLive International popularized the term Web 2.0 for a conference they hosted after Dale Dougherty mentioned it during a brainstorming session. Dougherty suggested that the Web was in a renaissance, with changing rules and evolving business models. The participants assembled examples — "DoubleClick was Web 1.0; Google AdSense is Web 2.0. Ofoto is Web 1.0; Flickr is Web 2.0" — rather than definitions. Dougherty recruited John Battelle for a business perspective, and it became the first Web 2.0 Conference in October 2004. A second annual conference was held in October 2005.
In their first conference opening talk, O'Reilly and Battelle summarized key principles they believe characterize Web 2.0 applications: the Web as platform; data as the driving force; network effects created by an architecture of participation; innovation in assembly of systems and sites composed by pulling together features from distributed, independent developers (a kind of "open source" development); lightweight business models enabled by content and service syndication; the end of the software adoption cycle ("the perpetual beta"); software above the level of a single device, leveraging the power of The Long Tail.
Earlier users of the phrase "Web 2.0" employed it as a synonym for "semantic web", and indeed, the two concepts complement each other. The combination of social networking systems such as FOAF and XFN with the development of tag-based folksonomies and delivered through blogs and wikis creates a natural basis for a semantic environment. Although the technologies and services that comprise Web 2.0 are less powerful than an internet in which the machines can understand and extract meaning, as proponents of the Semantic Web envision, Web 2.0 represents a step in its direction.
As used by its proponents, the phrase refers to one or more of the following:
The transition of websites from isolated information silos to sources of content and functionality, thus becoming computing platforms serving web applications to end users
A social phenomenon referring to an approach to creating and distributing Web content itself, characterized by open communication, decentralization of authority, freedom to share and re-use, and "the market as a conversation"
A more organized and categorized content, with a far more developed deeplinking web architecture
A shift in economic value of the web, possibly surpassing that of the dot com boom of the late 1990s
A marketing term to differentiate new web businesses from those of the dot com boom, which due to the bust now seem discredited
The resurgence of excitement around the possibilities of innovative web applications and services that gained a lot of momentum around mid 2005
Many find it easiest to define Web 2.0 by associating it with companies or products that embody its principles and Tim O'Reilly gave examples in his description of his four plus one levels in the hierarchy of Web 2.0-ness:
Level 3 applications, the most Wev 2.0, which could only exist on the internet, deriving their power from the human connections and network effects it makes possible and growing in effectiveness the more people use them. His examples were EBay, craigslist, Wikipedia, del.icio.us, Skype, Dodgeball, Adsense for Content, housingmaps.com and Amazon.
Level 2 applications, which can be offline but gain unique advantages from being online. His example was Flickr, benefiting from its shared photo database and community-generated tag database.
Level 1 applications are also available offline but gain features online. His examples were Writely, gaining group editing capability online and iTunes because of the music store portion.
Level 0 applications would work as well offline. His examples were MapQuest, Yahoo! Local, and Google Maps. Mapping applications using contributions from users to advantage can be level 2.
non-internet applications like email, IM clients and the telephone.
Examples other than those cited by O'Reilly include digg, Shoutwire, last.fm, and Technorati.
Commentators see many recently-developed concepts and technologies as contributing to Web 2.0, including weblogs, linklogs, wikis, podcasts, RSS feeds and other forms of many to many publishing; social software, web APIs, web standards, online web services, and others.
Proponents of the Web 2.0 concept say that it differs from early web development (retrospectively labeled Web 1.0) in that it moves away from static websites, the use of search engines, and surfing from one website to the next, towards a more dynamic and interactive World Wide Web. Others argue that the original and fundamental concepts of the WWW are not actually being superseded. Skeptics argue that the term is little more than a buzzword, or that it means whatever its proponents want it to mean in order to convince their customers, investors and the media that they are creating something fundamentally new, rather than continuing to develop and use well-established technologies.
The retrospectively-labeled "Web 1.0" often consisted of static HTML pages, rarely (if ever) updated. They depended solely on HTML, which a new Internet user could learn fairly easily. The success of the dot-com era depended on a more dynamic Web (sometimes labeled Web 1.5) where content management systems served dynamic HTML web pages created on the fly from a content database that could more easily be changed. In both senses, so-called eyeballing was considered intrinsic to the Web experience, thus making page hits and visual aesthetics important factors.
Proponents of the Web 2.0 approach believe that Web usage has started increasingly moving towards interaction and towards rudimentary social networks, which can serve content that exploits network effects with or without creating a visual, interactive web page. In one view, Web 2.0 sites act more as points of presence, or user-dependent web portals, than as traditional websites. They have become so advanced new internet users cannot create these websites, they are only users of web services, done by specialist professional experts.
Access to consumer-generated content facilitated by Web 2.0 brings the web closer to Tim Berners-Lee's original concept of the web as a democratic, personal, and DIY medium of communication.