Here are a few terms that have faded from everyday use over the past 10 to 20 years and this info should be helpful for 20-somethings; when the more senior people in your life use one of these terms, you'll know what they're talking about. 
Popular in the mid-90s, the term "intranet" usually referred to a private business network running the Internet Protocol and other Internet standards such as HTTP. It was also used to describe an internal Web site that was hosted behind a firewall and was accessible only to employees. Today, every private network runs IP, so you can just use the term virtual private network or VPN to describe a private IP-based network.
An "extranet" referred to private network connections based on Internet standards such as IP and HTTP that extended outside an organization, such as between business partners. Extranets often replaced point-to-point electronic data interchange (EDI) connections that used standards such as X12. Today, companies provide suppliers, resellers and other members of their supply chain with access to their VPNs.
3. Web Surfing
When is the last time you heard someone talk about surfing the Web? You know the term is out of date when your kids don't know what it means. To teens and tweens, the Internet and the World Wide Web are one and the same thing. So it's better to use the term "browsing" the Web if you want to be understood.
4. Push Technology
The debate over the merits of "push" versus "pull" technology came to a head in 1996 with the release of the PointCast Network, a Web service that sent a steady stream of news to subscribers. However, PointCast and other push technology services required too much network bandwidth. Eventually, push technology evolved into RSS feeds, which remain the preferred method for publishing information to subscribers of the Internet. RSS stands for Really Simple Syndication.
5. Application Service Provider (ASP)
During this decade, the term "Application Service Provider" evolved into "Software-as-a-Service." Both terms refer to a vendor hosting a software application and providing access to it over the Web. Customers buy the software on a subscription basis, rather than having to own and operate it themselves. ASP was a hot term prior to the dot-com bust. Then it was replaced by "SaaS." Now, the latest buzz is to talk about "cloud computing."
6. Personal Digital Assistant (PDA)
Coined by former Apple CEO John Sculley back in 1992 when he unveiled the Apple Newton, the term "personal digital assistant" referred to a handheld computer. PDA was still in use in 1996, when the Palm Pilot was the hottest handheld in corporate America. Today, the preferred generic term for a handheld like a Blackberry or an iPhone is a "smartphone".
7. Internet Telephony
You need to purge the term "Internet telephony" from your vocabulary and switch to VoIP, for Voice over IP. Even the term VoIP is getting old-fashioned because pretty soon all telephone calls will be routed over the Internet rather than the Public Switched Telephone Network. It's probably time to stop referring to the PSTN, too, because it is headed for the history books as all voice, data and video traffic is carried on the Internet.
A blog is a shortened version of "Weblog," a term that emerged in the late 1990s to describe commentary that an individual publishes online. It spawned many words still in use such as "blogger" and "blogosphere." Nowadays, few people have time to blog so they are "microblogging," which is another word that's heading out the door as people turn Twitter into a generic term for blasting out 140-character observations or opinions.
9. Thin Client
You have to give Larry Ellison credit for seeing many of the flaws in the client/server computing architecture and for popularizing the term "thin client" to refer to Oracle's alternative terminal-like approach. In 1993, Ellison was touting thin clients as a way for large organizations to improve network security and manageability. Although thin clients never replaced PCs, the concept is similar to "virtual desktops" that are gaining popularity today as a way of supporting mobile workers.
10. World Wide Web
Nobody talks about the "World Wide Web" anymore, or the "Information Superhighway," for that matter. It's just the Internet. It's a distinction that Steve Czaban, the popular Fox Sports Radio talk show host, likes to mock when he refers to the "Worldwide Interweb." Nothing dates you more than pulling out one of those old-fashioned ways of referring to the Internet such as "infobahn" or "electronic highway."
 Source: Carol Duffy Marsan, 8/09