Introduction to Computers Essential Understanding of Computers and Computer Operations
Topics • The term “computer” • Four basic computer operations • Data and information • Principal components of computer • Data storage devices and usage • Software • The Internet & WWW
What is a Computer? • A programmable machine that inputs, processes, and outputs information • An electronic device for storing and processing data • Composed of hardware and software • Can exist in a variety of sizes and configurations
Examples
What Do Computers Do? • Input, Process, Output, & Store data Output Input Process Store Data
Input, Processing, Storage, and Output Devices
What is Data? • The raw material of information • Contain facts w/o interpretations • The information entered into, and stored within a computer or file • Used by applications to accomplish tasks • Unprocessed information • E.g. text, numbers, images, audio, & video
What is Information? • Contains meaning, knowledge, instruction, communication, & representation of data • Result of processing, manipulating and organizing data in a way that adds to the knowledge of the person receiving it • The output of information systems
Flow of Computing • Data Processing Information • Example Retrieve data Calculate weekly wage:$25 X 40 hours = $1000 Send information to output device Pat Brown1001 Jump StreetShoreline, WA 98123$25 per hour40 hours
Principal Components of Computer • Input devices • System units • Storage (memory) devices • Importance of Saving • Output devices
Input Devices • Keyboard, mouse, scanner, & etc
System Units • CPU (Central Processing Unit) • Random Access Memory (RAM) • Secondary Storage Devices
Central Processing Unit (CPU) • Main processor of a computer that makes everything work • Interprets & carries out the basic instructions • Performs all the instruction, logic, & mathematical processing
Storage (memory) Devices • Two types: • Primary & Secondary • Primary: • Temporary memory for dynamic access by the processor (CPU) • RAM (Random Access Memory) • Secondary: • For large data storage, e.g. hard disk drive • RAM is much faster than disk drives for dynamically interacting with the processor
Random Access Memory (RAM) – the Primary Memory • Temporarily stores instructions and data waiting to be processed by the processor • Memory units are measured in kilobytes, megabytes, or gigabytes • 1 kilobytes = 1,000 bytes = 1,000 memory locations ≈ 1,000 characters • 1 megabyte (MB) = 1 million memory locations • 1 gigabyte (GB) = 1 billion memory locations • E.g. 512 MB = 512 million characters1 MB can hold approx. 500 pages of text
Secondary Memory (Semi-permanent) • Magnetic Disks • Hard disks, floppy disks, zip disks • Optical Disks • CD-ROM, CD-R (Recordable), CD-RW, DVD • Flash Memory Cards • USB flash drive: Small, lightweight, & large storage capacity
Importance of Saving and Saving Often • When using an application, data is stored in RAM temporarily • When the file, application, or computer closes, the data in the RAM is erased • Where do I save the files? • At the Lab: Removable disks such as floppy, zip, or USB. • At home: Hard drive (C:\) or any removable disk. • Never remove a disk while the light flashes • Saving on an existing file replaces the old data with new (Save vs. Save As)
Importance of Data Backup • All secondary storage devices such as floppy and hard drive disks eventually fail, and you lose the data • Make backup files weekly, if not daily • If you have a computer, use the hard drive or a removable disk as your backup • Otherwise, use the second removable disk
Output Devices • Printers • Monitors • and more
Personal Computers • PC, Mac, and other microcomputers • Desktop, Laptop, PDA • Windows, Mac OS, Linux, etc. • Increasingly more capable, portable, affordable, and mobile
System Software • Manages computer operations • Instructs computer how to perform functions of loading, storing, and executing an application software and how to transfer data • Examples: Windows, Mac OS, Linux, & etc.
Application Software • Programs that tell a computer how to perform tasks and produce information • Categories: • Word processing • Spreadsheet • Database • Presentation graphics • Web and Internet access • Desktop publishing / image editing / multimedia editing
The Internet and WWW • The Internet is the world’s largest network • Uses: • Send messages (e-mail) • Access a wealth of information • Electronic commerce • Online meeting • Access entertainment and multimedia • WWW (World Wide Web) • The more popular component of the Internet • Web page: A document containing text, hyperlinks, images, & other multimedia contents • Web site: A collection of Web pages
Communications Devices • Modem • Network card • Router • Wireless modem, network card, & router
