Technical Terms / Devices:
| bit | binary digit – the smallest unit of information, expressing a state of 0 or 1 |
| byte | a group of 8 bits operated on as a unit and storing a meaningful instruction or data |
| kilobyte (kb) | storage unit of 1024 bytes (= 210 bytes) |
| megabyte (Mb) | 1024 kb (= 220 bytes) |
| gigabyte (Gb) | 1024 Mb (= 230 bytes) |
| nanosecond (ns) | 10-9 seconds; the timescale at which main memories can receive and supply information |
| ROM | read-only memory – information fixed in the memory and cannot be overwritten |
| RAM | random-access memory – memory unit used to store instructions and data in active use; can be overwritten and is often ephemeral |
| mouse | pointing device to indicate selection of items on the screen |
| digitizer | used to capture graphic information by recording points on maps or figures |
| optical scanner | captures a paper image in a form that the computer can use |
| video scanner | captures a video image in a form that the computer can use |
| OCR | optical character recognition – software to interpret a scanned image as text for word processing |
| VDU | visual display unit – displays text and graphics as output and input to CPU |
| floppy disk | back-up and porting medium (a 3½” DS/HD floppy holds 1.44 Mb) |
| Graphical User Interface (GUI) | A program that helps you more easily work with you operating system and application programs by providing pictures and visual clues to help you work. Windows is the GUI on PCs. |
| NIC (Network Interface Card) | A card is put in the computer allowing connection to a network. |
| Port | Connection on the computer that allows input devices like monitors, disk drives, the mouse, or keyboards. Common ports are serial for connecting a modem or a mouse, USB for connecting a scanner, digital camera, Ethernet ports for connecting to a network, and audio in/out ports for connecting to headphones or a microphone. |