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Information Systems 511
Information Systems
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Faculty of
Information Technology
Information Systems 511
Year 1 Semester 1
2
Registered with t he Departme nt of Higher Education a s a Private Higher Education I nstitu tion under the Higher Ed ucation Act, 1997. Regi stration Certificate No. 2000/HE 07/
FACULTY OF INFORMATION TECHNOLOGY
LEARNER GUIDE
MO DULES: , 1 ) 250 $ 7 , 2 1 6 < 67 ( 06 5 (1ST SEM ESTER)
PREPARED ON BEHALF OF RICHFIELD GRADUATE INSTITUTE OF TECHNOLOGY (PT Y) LTD
Copyright © 2021 RICHFIELD GRADUATE INDTITUTE OF TECHNOLOGY (PT Y) LTD Registration Number: 2000/000757/ All rights reserve d; no part of this publication may be reproduced in a ny fo rm or by any means, including photocopying machines, without the written permission of the Institution.
TOPIC 5 OPERATING SYSTEMS
- 4 Audio output
- 5 Introduction to operating systems
- 5 Functions of an operating systems
- 5 Types of Operating Systems
- 5 Server Oparating Systems
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TOPIC ONE | INTRODUCTION TO COMPUTERS AND TODAY’S TECHNOLOGY
Learning Outcomes
- Define the term computer
- Defferentiate among laptops, tablets, desktops and servers
- Describe the relationship between data and information
- Differentiate between internet from the web, and describe the relationship among the web, web pages, websites and web servers
- Explain the purpose of browser, search engines, and an online social network
- Describe the purpose and uses of smartphones, digital cameras, portable and digital media players, e-book readers, wearable devices, and game devices
- Identify technology used by home users, small office/home office users, mobile users, power users, and enterprise users
- Briefly describe digital security risks associated with viruses and other malware, privacy, your health, and the environment.
1 COMPUTER TODAY
The term "computer" was originally given to humans (human computers) who performed numerical calculations using mechanical calculators, such as the abacus and slide rule. ...
Today’s computers are an electronic device, operating under the control of instructions stored in its own memory, that can accept data(input), processes the data according to specified rules, produce information (output), and store the results or information for future use. Computers process data to create information. Data is a collection of raw unprocessed facts, figures, and symbols. Information is data that is organized, meaningful, and useful. To process data into information, a computer uses hardware and software.
After reading this Section of the guide, the learner should be able to:
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the information is organized, identify the best sources of information for a given need, locate those sources, evaluate the sources critically, and share that information. It is the knowledge of commonly used research techniques.
1.2 ADVANTAGES OF USING COMPUTERS The benefits of computers are possible because computers have the advantages of speed, reliability, consistency, storage, and communications.
- Speed : When data, instructions, and information flow along electronic circuits in a computer, they travel at incredibly fast speeds. Many computers process billions or trillions of operations in a single second.
- Reliability : The electronic components in modern computers are dependable and reliable because they rarely break or fail.
- Consistency : Given the same input and processes, a computer will produce the same results consistently. Computers generate error-free results, provided the input is correct and the instructions work.
- Storage : Computers store enormous amounts of data and make this data available for processing anytime it is needed.
- Communications: Most computers today can communicate with other computers, often wirelessly. Computers allow users to communicate with one another.
1.2 DISADVANTAGES OF USING COMPUTERS Some disadvantages of computers relate to the violation of privacy, public safety, the impact on the labor force, health risks, and the impact on the environment.
- Violation of Privacy : In many instances, where personal and confidential records were not properly protected, individuals have found their privacy violated and identities stolen.
- Public Safety : Adults, teens, and children around the world are using computers to share publicly their photos, videos, journals, music, and other personal information. Some of these unsuspecting, innocent computer users have fallen victim to crimes committed by dangerous strangers. - Impact on Labor Force : Although computers have improved productivity and created an entire industry with hundreds of thousands of new jobs, the skills of millions of employees have been replaced by computers. Thus, it is crucial that workers keep their education up- to-date. A separate impact on the labor force is that some companies are outsourcing jobs to foreign countries instead of keeping their homeland labor force employed.
- Health Risks : Prolonged or improper computer use can lead to health injuries or disorders. Computer users can protect themselves from health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks. Another health risk, called computer addiction, occurs when someone becomes obsessed with using the computer.
- Impact on Environment: Computer manufacturing processes and computer waste are depleting natural resources and polluting the environment. Strategies that can help protect
the environment include recycling, regulating manufacturing processes, extending the life of computers, and immediately donating replaced computers.
1 CATERGORIES OF A COMPUTER
In addition to differences in size, speed, processing capabilities, and price, other factors, such as the size of main memory and number of peripheral devices, also can be considered when categorizing computers. Rapid changes in technology make it difficult to define categories precisely. As a rule of thumb, today’s PCs have about as much memory and processing power as the mainframes of a decade ago. There are six major categories of computers are personal computers, handheld computers, Internet appliances, mid-range servers, mainframes and supercomputers.
1.3 Personal computers This is one of the popular categories of a computer. The personal computer is a computer that can perform all its input, processing, output and storage activities by itself and is intended to be used by one person at a time. PCs are intended to be operated directly by an end-user with only a general knowledge of computers, rather than by a computer expert or technician.
Types Of Personal Computers Types of personal computers includes laptops, tablets, and desktops. Laptops and tablets can sometimes be called mobile computers. A mobile computer is a portable personal computer, designed, so that a user can carry it from place to place. A user is anyone who interacts with a computer or mobile device, or utilises the information it generates.
Laptops
Fig 1. A Laptop is also called notebook computer. It is a thin, lightweight mobile computer with a screen in its lid and a keyboard in its base. A laptop is a portable computer that has most, or all, of the
A desktop computer is a personal computer designed to be in a stationary location, where all of its components fit on or under a desk or table. It is designed for regular use at a single location on or near a desk or table due to its size and power requirements. On many desktops the screen is housed in a device that is separate from the tower, which is a case that contains the processing circuit. Some desktop usually called all-in -one desktops, do not contain a tower and instead use the same case to house the screen and the processing circuit. With today’s technology, some screens for desktops support touch.
Servers
Fig 1. A server is a computer dedicated to providing one or more services to other computers or devices on a network. Server is a computer program or a device that provides functionality for other programs or devices, called "clients". Servers can provide various functionalities, often called "services", such as sharing data, storing content, controlling access to hardware, software or resources among multiple clients, or performing computation for a client. A single server can serve multiple clients, and a single client can use multiple servers. A client process may run on the same device or may connect over a network to a server on a different device. A network is a collection of computers and devices connected together, often wirelessly.
1 CATERGORIES OF MOBILE GAME COMPUTERS
A mobile device is a small computing device, typically small enough to be handheld (and hence also commonly known as a handheld computer or simply handheld ), having a display screen with a miniature keyboard (either alphabetic, numeric or alphanumeric) and, in some models, a touchscreen which enables the user to use a "virtual keyboard" that is displayed on screen, along with other icons and "buttons" that can be pressed.
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Popular types of mobile devices are smartphones, digital cameras, portable media players and e- book reader.
1.4 TYPES OF MOBILE DEVICES Smart Phones
A smartphone is an Internet-cable phone that usually also includes a calendar, an appointment book , an address book, a calculator, a notepad, games, and serveral other apps (which are programs on a smart phone).Mobile phones or smart phones are also known as cell phones with an advanced mobile operating system which combines features of a personal computer operating system with other features useful for mobile or handheld use. Many smart phones have touch screens and some have mini built in key board.
Fig 1. Three popular types of messages that you can send with smart phone Text Messages It is a short note, typically fewer than 300 charecters, sent to or from a smartphone or other mobile device. Picture message It is a photo or other image, sometimes along with sound and text, sent to or from a smartphone or other mobile device. A phone that can send picture messages is called a camera phone. Video message Is a short video clip, usually about 30 seconds, sent to or from a smartphone or other mobile device
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playing digital media such as audio, images, and video files. The data is typically stored on a CD, DVD, flash memory, microdrive, or hard drive. Most portable media players are equipped with a 3 mm headphone jack, which users can plug headphones into, or connect to a boombox or hifi system. Portable media players usually include a set of ear buds, which are small speakers that rest inside each ear canal.
E-Book Readers
Fig 1. E-book reader or e-book device , is a mobile electronic device that is designed primarily for the purpose of reading digital e-books or electronic version of a printed book and periodicals-book reader is a short for electronic book reader.
Game Devices A game console is a mobile computing devices designed for single- player or multiple player video games. Gamers ofen connect the game console to a television so that they can view their gameplay on the television’s screen.
Fig 1.
1 DATA AND INFORMATION
With computers, the processes Data (inputs) into information (output) and often store the data and resulting information for future use. Data is a collection of unprocessed items, which can include text, numbers, images, audio, and video**.** It is raw, unorganized facts that need to be processed. It can be something simple and seemingly random and useless until it is organized. Information conveys meaning to users. information is useful and usually formatted in a manner that allows it to be understood by a human.
Fig 1.
Input An input devices is any hardware component that allows you to enter data and instructions into a computer or mobile device. An input device is a peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or information appliance. Types of Input Devices Keyboard Pointing methods Voice and video input Scanners
Types of Output Devices Printers Displays Speakers
Fig 1. The World Wide Web is a global library of information available to anyone connected to the Internet. The World Wide Web, or just "the Web," as ordinary people call it, is a subset of the Internet. The Web consists of pages that can be accessed using a Web browser. The Internet is the actual network of networks where all the information resides. Things like Telnet, FTP, Internet gaming, Internet Relay Chat (IRC), and e-mail are all part of the Internet, but are not part of the World Wide Web.
Fig 1.
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1.6 Web Browsing
A browser is software that enables users with an Internet connection to access and view webpages on a computer or mobile device.
Fig 1. 1.6 Web Searching
A search engine is software that finds websites, webpages, images, videos, news, maps, and other information related to a specific topic
Fig 1.
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and security risks to private information and property associated with using the internet, and the self-protection from computer crime in general.
1.7 Viruses And Other Malware Malware is short for malicious software, is software that acts without a user’s knowledge and deliberately alters the computer’s and mobile device’s operations. Examples of malware include viruses, worms, Trojan horses, rootkits, spyware, adware, and zombies. Each of these types of malware attacks your computer or mobile device differently. A computer virus is a malicious piece of executable code that propagates typically by attaching itself to a host document that will generally be an executable file. Virus is a program written to enter to your computer and damage/alter your files/data. A virus might corrupt or delete data on your computer. Viruses can also replicate themselves.
Virus is of different types which are as follows.
File viruses
Macro viruses Master boot record viruses
Boot sector viruses
Multipartite viruses
Polymorphic viruses
Stealth viruses
Worms are malicious programs that make copies of themselves again and again on the local drive, network shares, etc. The only purpose of the worm is to reproduce itself again and again. It doesn’t harm any data/file on the computer. Unlike a virus, it does not need to attach itself to an existing program. Worms spread by exploiting vulnerabilities in operating systems.
1.7 Privacy Information privacy , or data privacy (or data protection) , is the relationship between collection and dissemination of data, technology, the public expectation of privacy, and the legal and political issues surrounding them. In many instances, where personal and confidential records were not protected properly, individuals have found their privacy violated and identies stolen.
1.7 Health Concerns Computer users can protect themselves from health risks such as disorder of the hands, wrists, elbows, eyes, neck and back through proper workplace design, good posture while at the computer, and appropriately spaced worked breaks. Two behavioural health risks are technology addiction and technology overload. Technology occurs when someone becomes obsessed with using technology. Individuals suffering from technology overload feel distressed when deprived of computers and mobile devices.
1.7 Environmental Issues Manufacturing processes for computers and mobile devices along with e-waste, or discarded computers and mobile devices, are depleting natural resoures and polluting the environment. Green computing involves reducing the electricity consumed and environmental waste generated when using a computer. Green computing is the environmentally responsible and eco-friendly use of computers and their resources. In broader terms, it is also defined as the study of designing, manufacturing/engineering, using and disposing of computing devices in a way that reduces their environmental impact.
Strategies that supports Green computing include: Recycling Using energy efficient hardware and energy saving features Regulating manufacturing processes Extending the life of computers Immediately donating or properly disposing of replaced computers
1 PROGRAMS AND APPS Software also called program, consists of series of related instructions, organised for a common purpose, that tells the computer what tasks to perform and how to perform them. Software is often divided into two categories. Systems software includes the operating system and all the utilities sometimes called tools that enable the computer to function. Applications software includes programs that do real work for users. For example, word processors, spreadsheets, and database management systems fall under the category of applications software.
1.8 Operating Systems Operating systems is a set of programs that coordinates all the activities among computer or mobile device hardware. It provides a means for users to communicate with the computer or mobile device and other software.
Information Systems 511
Course: Information Systems
University: Richfield Graduate Institute of Technology
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