Flashcards
Computer studies Revision
Flashcards do conjunto (30)
- 1What is a computer network?a set of computers linked wired or wireless for the purpose of sharing information.
- 2describe LAN and WANLAN-local area network-computer network that interconnects computers within a limited area.small geographical area
WAN-wide area network- covers a larger geographical distance/area - 3What are the advantages of a computer network?People can share information freely.
Anyone can connect to a computer network. - 4disadvantages of a computer networkDisruptions can occur frequently.
Cost of network. The cost of implementing the network including cabling and hardware can be pricey.Security Concerns. One of the chief downsides of computer networks involves security issues. - 5What devices are needed to produce a LAN?computer
Network interface card
router
Wireless access point
hub/switch - 6What is the difference between a Hub and a Switch?a switch is used to connect various network segments. A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). A Hub connects multiple Ethernet devices together, making them act as a single segment.
- 7What is the Internet?The Internet is the biggest world-wide communication network of computers
A computer network providing different information - 8What is the World Wide Web?A part of the internet that contains websites and web-pages, runs on the internet.
- 9What is the purpose of an ISP?An Internet Service Provider (ISP) is a company that provides Internet access to companies, families, and even mobile users
- 10What is an IP address?numbers used to identify a site on the internet. A string of numbers used by computers to locate computers that hold resources on the internet
- 11What is the purpose of a NIC?A network interface card is a circuit board that allows a computer to connect to a network.
- 12What is the purpose of a Router?The main purpose of a router is to connect multiple networks and forward packets destined either for its own networks or other networks.
Used to physically link computers using cables.Have multiple ports to connect computers into. - 13What is the purpose of a Hub?A Hub connects multiple Ethernet devices together, making them act as a single segment.
- 14What is the purpose of a Switch?Connect multiple hosts: Normally, a switch provides a large number of ports for cable connections, allowing for star topology routing. It is usually used to connect multiple PCs to the network.
- 15What is the purpose of a WAP?In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network.
- 16What is the purpose of a web browser?Web Browser. A web browser is an application used to access and view websites. Common web browsers include Microsoft Internet Explorer, Google Chrome, and Apple Safari. The primary function of a web browser is to render HTML, the code used to design or "mark up" web-pages
- 17What is a URL?Universal Resource Locator-Logical words used by humans to easily locate resources (like webpages) on the internet.
- 18How is a URL constructed?The URL is created in one of two ways
Using the URL of this article as an example, the three basic parts of a URL you should understand are the protocol, the domain name and the path - 19Explain the role of the DNSThe main function of DNS is to translate domain names into IP Addresses, which computers can understand.
It is a databases of URLs and their matching IP address. The service converts the URL requests into IP addresses for computers to understand - 20what is the difference between url and ip addressthe url is constructed of lettersand words whereas the ip address is constructed of only numbers.
- 21What are the three different network topologies?star, bus, ring
- 22What are the advantages / disadvantages of a Star topology?advantages-It is very reliable – if one cable or device fails then all the others will continue to work
it is fast and efficient as no data collisions can occur
disadvantages-it is expensive to install as this type of network uses the most cable (network cable is expensive)
extra hardware is required (hubs or switches) which adds to cost
if a hub or switch fails, all the devices connected to it will have no network connection - 23What are the advantages / disadvantages of a Ring topology?ADVANTAGES-Speed: Fast. Data transfers quickly, even if there are a large number of devices connected because the data only flows in one direction, so there won’t be any data collisions.
Cheap to set up. No additional hardware needed
DISADVANTAGES-Unreliable: If one computer goes down, it affects all others on the ring - 24What are the advantages / disadvantages of a Bus topology?ADVANTAGES-Easy installation
Cheap. Single cable.
Easy to add/remove devices
DISADVANTAGES-Unreliable: If the main cable fails the network goes down
Slow Speed: The more workstations, the slower the connection speed due to increased traffic
Security: Data travels to all computers. Risk of interception - 25List examples of data that need to be kept secureemails, passwords, accounts
- 26What is a Pigpen Cypherpigpen cypher is a type of encryption used to protect data by using symbols for each letter
- 27What is a Caesar CypherCaesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. the alphabet is shifted a certain amount of times so the data is then encrypted.
- 28What is encryption?ENCRYPTION is when you scramble a message or data (called PLAINTEXT) using CIPHER to make it difficult to read
the scrambled message is called CIPHERTEXT
a key is used to DECRYPT data back to PLAINTEXT - 29What is decryption?decryption is when a set of data has been encrypted into ciphertext and it is unscrambled back to plaintext so it can be read
- 30Why encrypt data?we encrypt data to stop it from being stolen. Encryption can not stop data from being intercepted but it can stop the data from being read by the wrong person
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- Year 8 Computing FlashCards sobre Computer studies Revision, criado por Darcey Brown em 09-03-2020.
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- Darcey Brown
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