19375645
Description
Flashcards by Jack Warner, updated more than 1 year ago
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Created by Jack Warner
about 5 years ago
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| Question | Answer |
| How many bits in a byte? | 8 |
| What does HTML stand for? | Hypertext mark up language - a text based system for defining web pages |
| What is Binary? | A system of number using only two digits 0 and 1 (also called the base-2 system), unlike the decimal (or denary) system in everyday use that that uses ten (base-10) |
| Why does data need protecting? | Lots of personal/sensitive data. Have confidence in companies holding data. Protect against hackers. |
| What does ASCII stand for? | American Standard Code for Information Interchange |
| What is a Variable? | Space for a single piece of data, each variable has a data type. You can change variables once they have been set. |
| What is Boolean? | A data type, can be either true or false and requires only one bit of storage. |
| What is a String? | A data type, stores any number of characters, such as a person's name, address and postcode. |
| What is Malware? | A piece of software that is hostile or intrusive. Examples are viruses, spyware, trojan horses and ad ware. |
| What is Phishing? | An attempt to gain personal information (name, address, credit card details...). Usually through email. |
| What is RAM (Random Access Memory)? | 3 letters associated with volatile memory. Generally any information stored with in this type of memory will be lost after the power is switched off. |
| What is Encryption? | A method of scrambling data with a key code which makes data unintelligible. |
| What is a Pixel? | The smallest element of a bitmap image. |
| What is an Algorithm? | A sequence of unambiguous instructions to complete a task. |
| What is Hardware? | The physical components of a computer system. |
| What is Software? | The programs or instructions on a computer system. |
| What is Data? | numbers, characters or symbols that have no context or meaning. |
| What is a LAN? | Local Area Network. A network over a small geographical area. |
| What is a Central Processing Unit (CPU)? | Brain of the computer that performs instructions. |
| What is an Input? | Device used to input data into a computer system (e.g. keyboard, mouse, microphone, scanner, touch screen). |
| What is an Output? | Device that outputs information (such as sound, images, video, print outs) from a computer system to the user (e.g. monitor, printer, projector, speakers, printer). |
| What is a PDF file? | Portable document format - a file standard that displays a document accurately on any computer platform. |
| What is a Program? | A stored set of instructions for a computer to execute. |
| Serial communication | Bits are sent one signal at a time over a single wire . |
| Parallel communication | Signals (bits) are sent simultaneously over a number of parallel wires. |
| Simplex transmission | Data travels in one direction only. |
| Duplex transmission | Data can travel in both directions simultaneously using two cables. |
| Half-Duplex transmission | Data can travel in both directions along a single cable, but not simultaneously. |
| Bit rate and Baud | The speed of data is measured in bits per second (bps) The Baud rate is the rate at which the signal changes Baseband means one signal (bit) is sent at a time down a serial connection In standard baseband, bit rate = baud rate. |
| Bandwidth | The amount of data that can be carried at one time. |
| Parity bits | A bit that is either 1 or 0 to make the digits odd or even depending on the request. |
| Check digit | A digit at the end of a string of numbers designed to check for mistakes in input or transmission. |
| What does Modem stand for? | Modulator/Demodulator. |
| What is TCP (Transmission Control Protocol)? | • Breaks up messages sent over the Internet into small chunks called packets • Reassembles the packets at the other end • Detects errors • Resends lost messages. |
| What is IP protocol? | Routes the individual packets between sender and recipient. |
| What is HTTP (hypertext transfer protocol)? | It is used for accessing and receiving web pages in the form of HTML files on the Internet • The protocol requests the web server to upload the requested web page to the user’s browser for viewing. |
| What is HTTPS (hypertext transfer secure protocol)? | It encrypts the information so that it cannot be hacked. |
| IP addressing | • Every computer and other device connected to the Internet has an IP address • E.g. 81.101.137.12 • Packets are labelled with the sender’s and the destination IP addresses • Packets are sent across the Internet separately via different routes and reassembled at the end. |
| Network Interface Cards | • Built into every networked device • Wired or wireless. |
| MAC addressing | • A Media Access Control (MAC) address is assigned to each Network Interface Card (NIC) by the manufacturer • Your computer may have more than one MAC address, e.g. one for ethernet and one for wireless • And a mobile phone may have two different MAC addresses – one for wireless and one for bluetooth • A MAC address looks like this: 3B:14:E6:39:0A:2C. |
| Parts of a web address | www.abc.co.uk/images/logo.jpg • Hosted on the WWW • Name of the organisation • A Company • UK based • Folder location and filename on the site |
| Domain Name System (DNS) | • DNS technology allows you to type a name such as google.co.uk into your web browser • It translates the web address google.co.uk into an IP address • e.g. www.google.co.uk = 74.125.131.94. |
| DNS servers | • There are 13 DNS “root” servers worldwide which keep a complete database of all names and IP addresses • Other DNS servers lower down the hierarchy hold parts of the database • When a DNS server receives a request not in its database, it will pass the request on to another server until it reaches one with the matching name and IP address • Lower level DNS servers are owned by ISPs. |
| Cookies | • A cookie is a small data file that a server will put on a client computer • Next time the client accesses the same server, the cookie file will also be sent, identifying the client • This would explain why: • You get automatically logged in to a website • You see online adverts relevant to you and your recent searches • Website preferences are saved |
| The client and the server | • The client is a web browser such as Internet Explorer, Chrome or Firefox • The server is responsible for serving the web pages depending on the client/end user requirement. |
| The role of a browser | The user types a web address (URL) into the browser’s address bar • The client (i.e. the web browser) forwards this request to the server to access the web page • The server acknowledges the request and sends the HTML source code for the web page to the client • The client receives the page source code and renders it into a viewable web page. |
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