1973, ARPANET was extended to include the international community. The network continued to develop and by the early 1980s, the ‘Internet’ had grown to become a worldwide network of military, academic, and scientific research computers.
By 1986, the Internet was opening up to the general public. However, the real breakthrough that led to the Internet as we know it came when Tim Berners-Lee, a scientist working at CERN, a nuclear research facility, invented HTML, a computer language which made it easier to display text and images. He also invented HTTP, a reliable way of transferring information from computer to computer.
Since those early days, the Internet has continued
to grow and grow. By September 2009, according to Internet usage statistics, there were over 1.7 billion people using the Internet, just over 25% of the world’s population.
Unit 1, Lesson 4, Exercise D Lecture 5
≤1.10
Electronic mail, or e-mail, is a way of sending and receiving messages in digital form via a computer. E-mails can be sent through an organization’s internal communications network, known as an intranet, to which only members of the organization have access, or they can be sent through the Internet to anyone, anywhere in the world.
So what are the advantages of e-mail to the user? Well, firstly, compared to writing a letter, it’s very easy. You simply type a message, add the e-mail address of the recipient, and press ‘send’. And you can do all of this from your desk, or on the move using your laptop or mobile phone. Secondly, e-mail is a very fast way to communicate: in most cases, messages will arrive within minutes or sometimes seconds of being sent, whilst a letter may take several days to arrive. It’s also comparatively cheap. You can attach large files with different formats such as documents, photos or video clips to an e-mail. Finally, by setting up an e-mail group, or typing multiple e-mail addresses into the address box, it’s possible to send the same message to several people at the same time.
But of course, as with most things, there is a downside. Yes, e-mail is usually fast, but it’s possible for an e-mail to get lost in the system and not arrive. Sending individual e-mails is cheap, but the set-up costs can be expensive: you need a
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computer and an Internet connection. There’s also the problem of information overload – some businesspeople receive so many e-mails each day that they hardly have time to respond to them all – this may result in important e-mails going unnoticed. Another problem is ‘spam’ or ‘junk e-mail’. This is e-mail that you haven’t asked for but which is sent out to advertise products or services. However, possibly the biggest disadvantage of e-mail is that it can be used to introduce viruses to a computer – the virus can be sent as an e-mail attachment which activates itself when the attachment is opened, or it can be sent within the e-mail itself.
Unit 3, Lesson 2, Exercise B≤1.11
Part 1 OK. Is everyone here? Good, then let’s begin. We’ve seen how ICT is used in pretty much all areas of modern life – it helps us learn, do our work, communicate with other people, spend our leisure time, stay healthy and manage our day-to- day lives. We appreciate being able to watch satellite TV, buy groceries online and communicate with friends and family around the world. However, most people don’t think about the technology that enables us to do these things. In today’s lecture, we’re going to look at ICT systems, specifically the different types of ICT systems, the components that make up an ICT system, and the functions that ICT systems perform.
There are basically two types of ICT systems: embedded and general purpose. We’ll start with embedded systems. An embedded system is one which is fixed inside the device that it controls. I’ll repeat that: embedded systems are found in all sorts of everyday devices, from the automated teller machine outside your bank, to the washing machine in your kitchen and the car in your garage. Embedded systems are special-purpose systems that are pre-programmed to perform specific tasks. There is a big advantage to these embedded systems. They are relatively inexpensive to produce because, unlike a PC or a laptop, they are designed to perform a limited set of tasks. In other words, embedded systems can only do one task or set of tasks.
Now let’s have a look at general purpose systems. These are systems that can be set up to perform different tasks. They include supercomputers, mainframe computers and microcomputers. Think about your own laptop or PC. What are the different things you use your computer for? Well,
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