There are many different possible internet business models. Examples are virtual storefronts (amazon), auctions (ebay), information broker (travelocity), portals (yahoo), search engines (google). Although the internet hype ended in 2000, there are still ways to make money with internet business. Other companies did and do exist before and outside the internet (bricks-and-mortar), but still use so-called "clicks-and-mortar" web pages heavily to sell and buy (e-commerce) or to exchange and store information within the company. Unless the web sites are just a showroom, heavy scripts on the server side are necessary to personalize your web pages, to handle your order and the payment, and to
is about buying and selling over the internet. Amazon was, I think, one of the first success stories here. e-commerce could be B2C (Business-to-Consumer), B2B (Business-to-Business), or even C2C (consumer-to-consumer). Very important for the success are the ease of shipping (it is best if it can be sent over the internet, like music or programs) and the payment method.
Secure communication and payment is a crucial point in e-commerce. Therefore most business sites use SSL (Secure Sockets Layer) encryption for communication. Payment can be done by means of submitting the credit card number, electronic cash, person-to-person payment systems like paypal, and others.
There is a lot of advertisement on the web. Many internet business models (yahoo, google, ...) don't sell anything, but just get their money from advertisers. Whether people are just annoyed or really "click through", I can't tell. At least, advertisers make it possible that many things you would normally have to pay for (even server space) are free. Some sophisticated ads are even context-sensitive---you get messages related to your screen topic. Many advertisements come in the form of "banner-ads". Then there are the pop-over and pop-under ads, which open new windows. Even more tricky ads (seen at yahoo) hide the text you want to read for some time, showing a movie or animation. You may use programs to avoid (pop-up) ads.
means using intranets, private networks that can only be accessed from within a company, but use internet technology, or the internet for exchanging information and collaboration. Extranets are intranets that are open to some selected customers. It is also possible to send private data over the internet using a technology called "tunneling" and again encryption. Virtual private networks (VPNs) make use of this.