See Article History Internet, a system architecture that has revolutionized communications and methods of commerce by allowing various computer networks around the world to interconnect. By , approximately 4. The Internet provides a capability so powerful and general that it can be used for almost any purpose that depends on information, and it is accessible by every individual who connects to one of its constituent networks. It supports access to digital information by many applications, including the World Wide Web. See electronic commerce. By the early s computer manufacturers had begun to use semiconductor technology in commercial products, and both conventional batch-processing and time-sharing systems were in place in many large, technologically advanced companies.
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We will get slightly more precise and technical in the next section , for now let us address some elementary concepts. The number of the packets depends on the size of the data. For simplicity, let us think about the transmission of a text file.
Big train: several wagons, small train: few, maybe just one wagon. Each packet is like an envelope sent by normal mail, with the actual data, part of the original file, inside. We could summarize the journey of a file such as an e-mail message or a web page, from computer A to computer B, as follows.
As we mentioned, communication paths most often constituted by physical wires between computer A and computer F Figure on the Internet are often redundant. Physically, on the hardware level, there relays are constituted by Routers.
As the name implies, routers allow packets to find the best route between two computers that do not belong to the same network. Data are generally relayed through several such routers before they reach their final destination. The crucial thing to understand here, is that at any given time we re talking about milliseconds , the best route between 2 computers may change.
Routers are able to determine, at the moment of sending a particular packet, the best route at this time. When sending the next packet, the best route may be different.
Therefore, each packet from the same file could take a different route in order to reach the intended destination. The dialogue will end when all the packets have reached the destination.
Although this packet organization might seem complex, it has a number of advantages, with respect to an hypothetical model based on sending entire unfragmented files.
Bandwidth is limited, so this would be highly inefficient and would clutter the network. With packets, if something goes wrong with a packet, you just have to re-send this packet, not the whole file. The bandwidth is finite imagine you only have one rail. In order to send a small one packet file a one wagon train , you have to wait until the big file a 20 wagon train for example has passed.
If you fragment the 20 wagon train into the individual packets, and send one at a time, then the one packet train has a fair chance to go through together with the packets of the 20 wagons train.
As it works now, you can download your e-mail 50K while you download this big video file GB. This discussion is closely related to the concept of net neutrality.
In a condition of neutrality, all packets are equal, and have the same privileges and the same speed of transmission. In a non-neutral situation, a provider might, for example, limit the bandwidth or make this bandwidth more expensive , for certain kind of packets, for example those related to peer to peer traffic file exchange between users , or maybe those related to VoIP traffic, for commercial or other purposes.
We will get slightly more precise and technical in the next section , for now let us address some elementary concepts. The number of the packets depends on the size of the data. For simplicity, let us think about the transmission of a text file. Big train: several wagons, small train: few, maybe just one wagon. Each packet is like an envelope sent by normal mail, with the actual data, part of the original file, inside. We could summarize the journey of a file such as an e-mail message or a web page, from computer A to computer B, as follows.
By Monica Anderson and Andrew Perrin Although seniors consistently have lower rates of technology adoption than the general public, this group is more digitally connected than ever. In fact, some groups of seniors — such as those who are younger, more affluent and more highly educated — report owning and using various technologies at rates similar to adults under the age of Still, there remains a notable digital divide between younger and older Americans. And many seniors who are older, less affluent or with lower levels of educational attainment continue to have a distant relationship with digital technology. Four-in-ten seniors now own smartphones, more than double the share that did so in With smartphone ownership in the U. Smartphone adoption drops off considerably among adults in their mids and beyond.
Internet Technologies Tutorial
Many people use the terms Internet and World Wide Web aka. The Internet and the Web are two separate but related things. What is The Internet? The internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the internet.
Does your blog have a contact page? Internet and web technologies by rajkamal pdf free download Macros and Functions 14 Program Elements: Revathy A 18 October at None of your libraries hold this item. An Embedded System 3 raj,amal. Some things take longer than others to accomplish, so people must understand dezign they should have their eyes on the goal, and that should keep them motivated to see it out til the end. I am a regular reader of your blog and being students it is great to read that your responsibilities have not prevented you from continuing your study and resign activities. Separate different tags with a comma. Architecture, Programming, and Design, describes an embedded system as one with embedded hardware and software and describes the fundamentals of the architecture, design, and applications for these systems.