Computer Fundamentals

Measuring Units of Processing Speed

• Measuring units of processing speed: MHz, MIPS, MFLOPS

Input/Output Devices

• Input device: allows users to feed data into a computer for analysis and storage and gives commands to the computer
• Examples of input devices: Mouse, keyboard, Scanner, Joystick, Light pen, Trackball, Touch Screen, Microphone
• Keyboard: used for inputting text, numbers, and commands to the computer
• Mouse and Joystick: used to move the cursor position on a monitor screen
• Shift key: used to make characters either upper or lower case
• Tab key: used to move the cursor across the screen and to move the cursor down the screen

Output Devices

• Output device: communicates the results of data processed by the computer and converts digital information into a form that humans can easily read and understand
• Examples of output devices: Speaker, Headset
• Speaker: produces sound and is commonly used to listen to audio or receive auditory feedback from a computer or electronic device
• Headset: used for outputting audio, commonly used for listening to music, watching videos, making phone calls, or participating in online meetings

Other Devices

• Scanner: an input device used to convert physical documents or images into digital format
• Web camera: an input device that captures video and audio data and sends it to a computer or other device for processing or communication purposes
• Microphone: an input device that converts sound waves, or acoustic signals, into electrical signals
• Barcode reader: an input device used to input data into a computer system

Memory

• Types of memory: ROM, RAM, Cache, EEPROM
• ROM: non-volatile, meaning its data is retained even when the device is powered off
• RAM: volatile, performs both read and write operations, also called read-write memory (RWM)
• Cache: a small, very high-speed semiconductor memory, placed as a buffer between the CPU and RAM
• EEPROM: Electrically Erasable Programmable Read-Only Memory
• SRAM and DRAM: two types of Random Access Memory (RAM)

Basics of Internet

• The internet: a huge network of networks that joins computers from across the world
• The concept of the internet was originated in 1969
• Downloading: the transmission of a file from one computer system to another computer or to a server so that others can see or retrieve it
• IP address: a unique address assigned to each computer on a network
• TCP/IP: a protocol that allows computers to communicate with each other on the internet
• HTML: Hyper Text Markup Language
• www: also known as the web, developed by Tim Berners-Lee in 1989 at CERN in Geneva
• DNS: translates a domain name (computer host name) to IP address
• Top-level domain extensions: .com, .edu, .gov, .net

Web Servers and Protocols

• Web server: a computer that stores data or information for users on the internet
• FTP: File Transfer Protocol, a program that allows for easy transfer of computer files from one host to another host over a TCP-based network
• HTTPS: a protocol used to securely transfer data over the internet
• Decryption: the technique used to convert an encrypted message into the actual message