Computer Hardware and Software
August 15 – August 23
§ Introduction to Information Technology:
o Information technology (IT) is any computer-based tool that people use to work with information and support the information and information-processing needs of an organization (p. 39).
§ IT extends beyond the computer, but to many other tools that help you use information more effectively. A printer, for example, helps you use information by creating a “hard” paper copy. A local area network allows people to share information around the world. A cell phone allows you to communicate and even connect to the Internet. Software such as Microsoft Word can help you create letters and memos.
o IT tools can be broken down into two broad categories: hardware and software (p. 40).
§ Hardware is the physical devices that make up a computer.
§ Software is the set of instructions that your hardware executes to carry out a specific task for you. Software is the “go-between” that allows you to use the hardware.
§ Binary:
o A binary digit (bit) is the smallest unit of information that your computer can process (p. 51).
o A bit can either be “on” or “off”. Numerically, an “on” bit is represented by a 1 and an “off” bit is represented by a 0 (p. 51).
o Physically, an “on” bit is typically represented by one electrical voltage and “off” bit is typically represented by a different electrical voltage.
o These bits are formed into a series of eight bits, known as bytes. One byte represents one character (p. 51).
§ For example, c is represented by the following byte: 01100011.
o Computer storage is represented by the following terminology:
§ 1 megabyte (MB) = 1 million bytes (1 million characters)
§ 1 gigabyte (GB) = 1 billion bytes (1 billion characters)
§ 1 terabyte (TB) = 1 trillion bytes (1 trillion characters)
§ Hardware:
o Hardware can be broken down into six categories (p. 41).
§ Input device
§ Output device
§ Storage device
§ Central processing unit (CPU)
§ Telecommunications device
§ Connecting devices
o An input device is a tool that you use to provide information and commands.
§ Examples include the keyboard, microphone, mouse, scanner, point-of-sale (POS), etc. (pp. 52-53).
o An output device is a tool that allows you to see or hear the results of your information processing requests.
§ Examples include monitors, printers, and speakers (pp. 54-56).
o A storage device is a tool that allows you to store information for use at a later time (pp. 56-58).
§ These storage devices are permanent.
§ These storage devices are usually either magnetic surfaces or surfaces that reflect light (a.k.a. optical).
§ These devices are usually quite slow.
§ Common storage devices include:
Device / Type / SizeFloppy disk / Magnetic / 1.44 MB
Hard disk drive / Magnetic / Up to 100 GB
CD-ROM drive / Optical / 650-800 MB
DVD-ROM drive / Optical / 4.2-17 GB
o The central processing unit (CPU) is the actual hardware that interprets and executes the software instructions and coordinates how all the other hardware devices work together (p. 59).
§ Basically, the CPU is the “brain” of the computer.
§ The CPU works closely with random access memory (RAM).
§ RAM is temporary storage that stores data that the CPU is about to use. RAM is quick and electrical (p. 59).
o A telecommunications device is a tool you use to send information to and receive it from another person or location.
§ The common telecommunications device is the modem (p. 41).
o Connecting devices enable hardware devices, particularly those outside the computer, with the computer (pp. 61-63).
§ Software:
o There are two main types of software: application and system (p. 45).
o Application software is the software you use to meet specific information-processing needs. Examples include Microsoft Word, Internet Explorer, and Adobe Photoshop, etc. (p. 45).
§ Application software is broken into two categories: personal productivity software and vertical and horizontal market software.
· Personal productivity software is used to help individuals and includes things like word processing or photo editing (p. 45).
· Vertical and horizontal market software is used to help entire companies, and includes things like inventory management software (pp. 46-47)
o System software is the category of software that controls how your various hardware devices work together as you use your application software to perform specific information-processing tasks (p. 42).
§ The most popular type of system software is the operating system. The operating system controls your application software and manages your hardware (p. 42).
§ Utility software adds functionality to the OS. Examples include antivirus software, backup software, disk optimization software, etc (p. 42).