Networked computers

Networked Computers

•  Personal computers
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• Users access allocated connected to a server via resources via a user name network cards and cable sand password
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•  The software and data is Very popular with small-to-stored on the central medium-sized businesses, server rather than installed schools and colleges/adult individually on each PC education centers.
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• The network also enables fast Internet connection, printers and scanners tobe shared.

mainframe computers

Mainframe Computers

•         Large, fast and expensive  used by large organizations such a companies, banks or multinational companies.
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•        Connect hundreds or thousands of users
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•        Users connect via terminals which are located in different cities or even abroad.

Different Types Of Computer

Mainframe computers

Networked Computers

Personal Computers

Laptop/Notebook Computers 
Personal Digital Assistants/Handheld Computers

Hardware and Software

Hardware

Refers to the physical parts of a computer – those parwhich you can see or touch

Software

Primarily a list of instructions coded in a special way that computers can understand

•Operating system System software – eg Windows which works in the background and controls your software and hardware devices

•Applications software – eg Microsoft Word – software used to perform tasks

Facts about information Technology

1. 51% of internet traffic is “non-human”. 31% is made up from hacking programs, spammers and malicious phishing
2. A new identification system for the internet launches this week which means there can be trillions of new unique addresses made.
3. It would take 1,000,000 human brains to store all of the information that can be found on the internet.
4. A rare functioning Apple 1 computer – the company’s first product – has been sold at an auction for $374,500 (£240,929).
5. IBM’s Sequoia has taken the top spot on the list of the world’s fastest supercomputers for the US.
6. The first computer was almost 2.5 metres (8ft) high and weighed nearly 30,000kg – more than 600 times heavier than an average computer today.
7. Programmer Charley Kline sent the first computer-to-computer message in 1969; only the first two letters got through before the system crashed.  Today, over 80 billion emails are sent a day worldwide
8. Just one gigabyte (GB) in computer memory is the equivalent to storing a stack of documents that would reach around the height of an average two storey house. The average computer has around 100GB of memory.
9. IBM currently has the biggest data drive. At 120 petabytes, it can store 24 billion songs or back up the entire web 60 times.
10. The QWERTY layout used for English language computer keyboards is 135 years old.  It was originally invented for a new form of typewriter.
11. The first portable computer, the Osborne I, weighed 11.88kg (1stone 12lbs) and three ounces, and measured 52 cm (20.5 inches) wide.
12. The processor in the first Apple computer (the Apple I) is 1,000 times slower than today’s Apple iPad.

Data transmission

Data transmission has three aspects: transmission, propagation, and reception. It can be broadly categorized as broadcasting, in which information is transmitted unidirectionally downstream, or telecommunications, with bidirectional upstream and downstream channels.

XML has been increasingly employed as a means of data interchange since the early 2000s, particularly for machine-oriented interactions such as those involved in web-oriented protocols such as SOAP, describing "data-in-transit rather than ... data-at-rest". One of the challenges of such usage is converting data from relational databases into XML Document Object Model (DOM) structures.

Data retrieval

The relational database model introduced a programming-language independent Structured Query Language (SQL), based on relational algebra.

The terms "data" and "information" are not synonymous. Anything stored is data, but it only becomes information when it is organized and presented meaningfully. Most of the world's digital data is unstructured, and stored in a variety of different physical formats^[30][b] even within a single organization. Data warehouses began to be developed in the 1980s to integrate these disparate stores. They typically contain data extracted from various sources, including external sources such as the Internet, organised in such a way as to facilitate decision support systems (DSS).