Information technology (IT) is a technology which uses computers to gather, process, store, protect, and transfer information. Today, it is common to use the term Information and communications technology (ICT) because it is unimaginable to work on a computer which is not connected to the network.
The computer consists of:
- hardware – physical computer parts, palpable and visible
- software – set of commands that are “understandable” to the computer; instructions to its palpable parts, giving orders what to do
The basic principle of computers:
Data enters the computer through one or more input devices. The computer then processes the data and transmits the resulting data to output devices. Output devices can be human interfaces such as a screen or another electronic device such as a storage device or computer network.
The system unit consists of the following components:
- Motherboard – MBO
o a computer “backbone” responsible for communication between components and transmission of information
- Central Processing Unit – CPU
o functions: command execution, data transmission, computer function control o basic characteristics:
- speed (in MegaHertz (MHz), GigaHertz (GHz)) • amount of memory (Cache in Bytes)
- Random Access Memory – RAM
o a memory container for programs that are currently running and data that is being processed
o basic characteristics:
- speed (in MHz, GHz) • capacity (in Bytes)
- data rate class (DDR SDRAM, SDR SDRAM) ∙ Permanent Memory:
o Hard Disk Drive – HDD – device (memory) used for permanent data storage
- data is stored on magnetic platters; electromagnetic heads are used for reading and recording data with the exception of the newest disk types called Solid State Drive (SSD)
- basic characteristics:
▪ disk platters rotation speed (in RPM)
▪ capacity (in GB)
▪ connection interface (IDE, SATA) o Floppy Disk Drive – FDD
o optical disks – CD, DVD
- Graphics Processing Units (GPU)
o function: processing and displaying image on the monitor
o it consists of a graphics processor and its own working RAM memory o basic characteristics:
type of graphics processing units (ATI Radeon, Nvidia GeForce, or other) RAM size
connection interface/slot type
o Parallel Port o Serial Port
o Universal Serial Bus (USB)
Input and output devices
- Input devices:
- Output devices:
o keyboard o scanner o touchpad o mouse o trackball o joystick
o microphone o stylus
o camera (web, digital)
o monitor o projector o printer
o plotter o speakers
- The device that is both input and output: the touchscreen.
Common devices and media for storing and transferring data:
- hard disk
- USB flash drive
- diskette and ZIP diskette
- CD and DVD discs
- memory cards
- internal hard disk
- external hard disk
- network disk drive
- online storage device
Software – a computer program which, as opposed to hardware, is an intangible part of the computer, written to perform single or multiple tasks on a computer using the built-in hardware.
- operating systems (OS) – the basic program on your computer that is automatically loaded when the computer is started up:
o Linux (Debian, Ubuntu, Fedora, Knoppix…) o Microsoft Windows (XP, Vista, 7...)
o Mac OS X (Cheetah, Panther, Snow Leopard…)
- application software – some types of software that can be used on an installed operating system:
o office programs – OpenOffice.org, LibreOffice, Microsoft Office o antivirus program – Avira, Sophos, Kaspersky etc.
o Web browser: Mozilla Firefox, Microsoft Internet Explorer, Opera, Safari
E -accessibility options:
- voice recognition software,
- a screen reader,
- magnifying tool,
- on-screen keyboard.
- Mainframe Computer
o large, powerful and expensive computers,
o often used within large systems and organizations, o can be used by more than one user simultaneously.
- Personal Computer – PC
o first PC was made by IBM in 1981,
o it was originally made for executing a single task by a single user at the time. o today: a single person can execute many tasks simultaneously (multitasking).
- Apple Macintosh (Mac)
o personal computer made by Apple company,
- Laptop computer (notebook)
o relatively small computers, easily carried around, o consists of LCD display and a small keyboard,
o do not fall behind PCs by their functions
- Personal Digital Assistant – PDA (Palm)
o small computers that can fit into a pocket or user’s palm, o meant for performing basic personal/business functions:
- managing personal or business tasks and assignments, • maintaining the address book,
- accessing and browsing the Internet, • sending/receiving e-mails, etc.
o PDAs have now been replaced by modern smartphones that combine the features of a PDA with a mobile phone and camera.
- Network connected computer
o every computer (PC, notebook, PDA) connected to the network is considered a network computer; can be connected either through a network cable or through a phone line (at least to one more computer)
Beside notebooks and palms, there are other portable digital devices:
- mobile phone
- smartphone – a mobile phone with advanced functions such as e-mail, Internet browser, e-book reader
- multimedia player: iPod, iRiver, Zune
- LAN (Local Area Network) – a small network that physically connects nearby computers (computers within the firm, organization, or a household)
- WAN (Wide Area Network) – a larger network that covers a city or a region,
- Internet – a world network of connected computers, connected through WAN and LAN
- Intranet – a smaller network, closed version of internet to which only certain (authorized) people are granted access (members of an organization)
- Extranet – an intranet version, to which only certain people are granted access (not exclusively members of an organization, but also outsourced experts for performing common tasks),
- World Wide Web (WWW) – one of the services that can be used on Internet which enables us to view and search contents in a form of web-pages
- other services on the Internet that can be used:
o Instant messaging (IM) – Google Talk, Skype, Windows Live Messenger, Yahoo! Messenger
o Voice over Internet Protocol (VoIP) – protocol used for voice transfer over IP network; it basically enables us to use internet in order to make phone-calls
o Really Simple Syndication (RSS) – used for dissemination of information or articles etc. published on a web page using RSS channel (RSS news usually consists of title, few sentences and link to a web page where users can read the whole article). Users have to subscribe to RSS channel in order to receive news in their RSS reader. This eliminates a need for visiting a web page in order to find out latest news
o weblog →blog
o podcast – a digital file that contains audio or video record
- PSTN (Public Switched Telephone Network) – a technical expression for public telephone system
- ISDN (Integrated Services Digital Network)
- ADSL (Asymmetric Digital Subscriber Line) – most common communication standard in the consumer market
Internet data transfer:
- download – data storing from the internet onto personal computer ∙ upload – data storing from personal computer to internet server ∙ data rate units:
o bit per second (bps), kilobit per second (kbps), and megabit per second (Mbps). ∙ Internet access:
o dial-up – use of phone line in order to connect to the internet. The bill for the internet usage is directly proportional to the time spent on the Internet and/or the amount of data transferred.
o broadband – the bill is formed according to the speed of data transfer. Additionally, in areas where informational infrastructure for broadband is not developed enough (or for other reason), amount of data transfer is also charged. Unlike dial-up, time spent on the
internet is not charged and as a consequence, there is a greater risk from hacker intrusion in computers or networks that are connected to internet 24/7
o The Internet can also be accessed through phone, mobile, and cable line, as well as through wireless access or via satellite connection.
Virtual (online) communities
∙ social networking websites: Facebook, Bebo, Twitter, MySpace, LinkedIn, Nexopia, Hi5, Tagged, XING, Orkut, etc.
∙ Internet forums – Forum.hr, Download.hr, etc. ∙ chat rooms, e.g. Chat Rooms
∙ multiplayer games: Silkroad Online, Knight Online, Anarchy Online, Guild Wars, World of Warcraft
Ways to publish and share contents on the internet: blog, podcast, photos, video and audio contents.
Advice on how to protect oneself while using virtual communities:
- protect the privacy of your profile,
- limit publishing and use of your personal data,
- be aware that published information can be publicly accessible, ∙ be cautious while communicating with strangers.
The computer in the workplace:
- tasks more suited to a computer than a human: o repetitive tasks,
o easily automated tasks,
o mathematical operations,
o tasks that require high precision and speed.
- tasks more suited to a human than a computer: o logical reasoning and shape interpretation, o consulting and social interaction,
o new product presentation,
o developing business plan and strategies.
Information and Communication Technology (ITC) exists in every aspect of modern society. Some well-known applications include:
o applications for corporations (airlines, insurance companies, internet banking) o applications for state organizations (electronic voting, tax refund)
o applications for healthcare (data about patients, diagnostic tools and instruments, special surgical equipment)
o applications for education (computer based training – CBT, distance learning, e-learning): adaptive learning time, flexible learning location, multimedia learning experience, reduced costs.
Telecommuting (telework) ∙ Advantages:
o increasing the employment of vulnerable groups: parents with small children, people with mobility problems and people living in the remote areas,
o commuting time reduced or not necessary at all; cost and time of transportation to the workplace decreased or nonexistent
o greater possibility to concentrate on the job o flexible working hours
o reduced maintenance costs for the workspace
o lack of business human contact o lack of direct teamwork
o requires great self-discipline
ICT in everyday life:
o e-commerce o online banking o e-government
o online shopping o e-learning
- The most common health problems associated with the computer usage:
o repetitive, excessive or improper use of keyboard and mouse →RSI (Repetitive Strain Injury)
o flickering screen or working from an improper distance from the monitor →vision impairment, headache
o artificial light from monitors →insufficient light, improper contract or glare can cause eyestrain, headache and decreased productivity
o improper seating and the use of inappropriate chairs →spinal problems (position of the computer, desk and chair affect posture and can, therefore, create problems)
o well-being while using computers will improve through regular exercise, regular mini-breaks (5 – 10 minutes per hour) and rest frequent eye rest.
- cables – always use electric cables obtained with the computer ∙ power supply – overloading the power source may result in fire
- use of electronic documents reduces the need for printed material
- recycling of printed materials and printing equipment (paper and toners/cartridges) ∙ using monitors with lower energy consumption
- disposing damaged or old computer components at the recycling centre
- information security is defined as:
o preservation of information confidentiality, integrity and availability
o information security measures are the rules of data protection on the physical, technical and organizational level
- Increased level of the data security can be reached through the use of the following procedures:
o username and password
o properly shut down the computer
o The use of continuous power supply (UPS – Un-interruptible Power Supply) – in a case of power failure, without UPS your desktop computer will shut down and all data that are not saved on the hard disk will be lost. Documents should be often saved in order to narrow down the possibility of losing data but only UPS will enable saving your work as well as
shutting down the computer properly without losing anything. o professional maintenance of computer is recommended
o Creating backups of all important data on portable memory devices, network disk etc. (i.e. copy them from your computer to another location)
Malware – computer code – a program that can infect a computer, spread on other computers independently or with a help from a user thus stealing or damaging data, and enabling crackers to take over control of your computer.
most commonly spread via attachments in e-mail,
- symptoms of infection: slow performance, computer not responding to commands or crashes and restarts; in extreme situations, malware damages files responsible for proper functioning of the operating system which can totally disable the computer.
- removing malware: use one of the antimalware programs ∙ malware protection:
o never use pirated software which is usually infected with malicious software, o install antimalware software which detects computer malware,
o open e-mails and web pages from recognized senders and authors
(the safest way is not to connect to the Internet or any other computer network)
Copyright – the right of an author of the text, images, music, film, etc. to protect their intellectual property.
Product identification number (PID) is a number that comes with legally purchased software as an authenticity validation.
- Licensed software identification: serial number check-up, registration, software license inspection.
Software License Agreement- EULA (end-user license agreement).
Freeware – software free for personal use; for example, Adobe Reader.
Open source – software whose source code is publicly available for inspection, use, modification and redistribution; for example, OpenOffice.org – office suite software, Mozilla Firefox, Mozilla Thunderbird, MediaWiki, Joomla.
Shareware – programs that are free for temporary use at home.