Karteikarten
Unit 2 Revision
Karten in diesem Stapel (97)
- 1(Server)Runs special software to serve other computers.
Different types include file,print,web and emails servers. - 2(Client)A computer/device that uses services provided by a server.
The computer you use to access the internet is a client. - 3(Routers)Devices that route (direct) data traffic through a network.
They are intelligent and will try to find the best routes. - 4(Connection Method)Form the connections between all this hardware.
Includes all kinds of cable,such as fiber & telephone lines. - 5(Backbone)A `big` cable (often fiber optic) that connects a large number of devices in the `core` of the internet.
- 6(ISP)An ISP allows connection to the internet.
It would be too expensive to connect to the internet directly so the ISP gives an easy way of connection.
An ISP may provide connection to one `client` or a network of clients.For example a home network for a business network. - 7(Point Of Presence)A Point of Presence (POP) is an access point to the internet.
An ISP may have several Pop`s to allow good access to the internet. - 8(Network Access Point)
- 9(CLIENT)
- 10(Diagram)j
- 11(Dial Up Connections)Is a weird connection via modern & phone wires
Advantages: can use existing telephone wires.
Gives connection where broadband is not available.
Disadvantages:Older technology and can give poor connection.
Usually slower then that other methods. - 12(Broadband)Advantages: Better reception and speed dial-up
Disadvantages: Wired, so has be used on a stationary computer.
Broadband is not available in many rural places. - 13(Wireless)Advantages: not fixed to a stationary computer.
can be used whenever wireless internet is available (eg wi-fi hotspot).
Disadvantages: Needs to have wireless internet available.
Can be less secure than wired.
Tends to be slower than wired. - 14(Bandwidth) Bandwidth is how much capacity (space) there is to carry digital data as 1s and os. Measured in bits per second. High bandwidth means more data can be moved, so giving a faster internet connection and a higher transmission rate.
- 15Protocolprotocols are rules that allows computer system to connect with different systems to transfer data.
- 16Internet Protocol(IP)internet Protocol is responsible for:
Handling the routing of packets
That`s addressing,sending and receiving packets over the net. - 17Transmission Control Protocol(TCP)TCP is responsible for:
Breaking data into packets.
Assembling the packets again when they arrive. - 18File Transfer Protocol(FTP)Protocol which allows files to be transferred between two computers or devices.
It is usually used to upload or download files to a server. - 19—
- 20HTTPHyperText Transfer Protocol
HTTP is the set of rules that handle what we do on the web.
It handles your request to load a page from a web server.
It also handle the response to download to the web page and all its files to your computers. - 21HTTPSHyper Text Transfer Protocol Secure
The `s` in HTTPS means secure.
Data in the web page is scrambled before sending across the internet.
So if the data is intercepted, it can`t be understood.
Protects privacy from `hackers`. - 22FTPFile Transfer Protocol
An old protocol that was invented before the web was born.
It is still used to upload and download files from a server.
it is often used by web developers to transfer files to their web server.
But to use FTP, you usually need a username and a password. - 23Diagram
- 24Search EnginesSearch Engines are special websites that allow users to find data on the internet.
- 25Index & Databasethe search engine searches its index, which is its database of web pages.
- 26Sponsored LinksDon`t forget that the `Sponsored Links` will be placed at the top.
The more the company pays, the more likely it is to appear in the search results. - 27Spider/Web crawlerThey look around the web, looking for new or updated pages and log them in the search engine`s database called the index.
- 28Store and forwardS/F-Emails are stored in servers and then forwarded to the receiver.
Term used to describe that emails are first stored and then are forwarded. - 29Address Book/Contact GroupADD/C-A feature that can allow you to contact friends and also family and send them emails to them.
- 30CCCC-It means that recipients can see the message and also see who the other people have the message.
- 31BCCBCC-They can see the message but they can not see who else have got the message.
You choose to see what recipients see the message. - 32Benefits of using emailBOUE-They arrive in seconds much faster than traditional post.
Gmail & Hotmail use cloud servers so can access email everywhere. - 33Drawbacks of using emailDOUE-Spam or `Junk` email has a massive problem.
Fake emails designed to trick people to give personal details. - 34SMTP-Simple mail transfer protocol. It pushes outgoing email to the server. If ever a problem sending, them SMTP will keep trying until it is sent.POP 3- Post Office Protocol.
POP originally came before web mail when people used `email client software` eg MS Outlook.
You downloaded emails from the server. - 35IMAP-Internet Message Access Protocol. Lets you access your email on a server. When logon, you pull email from server. so you can access it `anytime, anywhere`.j
- 36Data Exchange
- 37Codecs
- 38Description of packet switchingPacket switching is the process of data being broken into `packets` before being sent through a network and then re-assembled at the other end.
- 39Advantages of packet switchingPackets choose different routes so traffic flow is efficient.
big files can still be sent but don`t clog network.
packets give security benefit because if intercepted, the hacker will only have one part of the file. - 40Disadvantages of packet switchingif one or more packets are lost or corrupted during transmission, the whole file will not be received correctly.
- 41Simplx with exampleSignals go in one direction at a time.
- 42Full duplex with exampleSignals go in both directions at same time
- 43Half duplex with exampleSignals go in both directions but not simultaneous
- 44Serial and parallel transmission descriptionSerial- bits of data are transferred one at a time over a wire.
Parallel-Bits of data are transferred simultaneously - a whole byte can be transferred at the same time. - 45Benefit and limitation of aboveSerial-Good over large distances.
complex because data has to be broken into individual bits.
Parallel-Faster because more bits transferred per second.
Only for shorter distances eg 5 meters. - 46Unshielded Twisted PairThey have no protection around the wires.
- 47Shielded Twisted PairThey are shielded around the wires so that it dosen`t get any interference.
- 48UTP&STP (Advantages) Contains pairs of copper wires twisted together. Used for LANS.-Cheaper than other methods.
-Reliable.
-Under plastic coating, the shielded (STP) -cable has protective layer around the -copper wires. - 49UTP&STP DisadvantagesSlow.
-Low capacity.
-Used over short distances.
-Susceptible to interference, which means -data can be interfered with if near another -digital device. - 50(Coaxial Cable) Is solid copper wire with thick shielding. Used to connect TV with aerial.(Advantage)
Reliable
(Disadvantages)
-Slow
-Low capacity
-Used over short distances
-Thick and physically inflexible
-Susceptible to noise
- 51(Fiber Optic) Strands of glass carry data as light. Used for backbone of network.(Advantages)
-Fast
-Used over long distances
-Little interference
(Disadvantages)
-Used for backbone of network - 52(Infrared) Uses infrared light to transmit data. Thats`s very high frequency light.(Advantages)
-Reliable
(Disadvantages)
-Short range
-Devices must be in line of sight
-Can suffer from interference
- 53(Microwave) uses waves with short wavelengths to transmit data.(Advantages)
-Good for medium distances
(Disadvantages)
-Can suffer from interference from other devices
- 54(Satellite) Uses satellites in space to relay data between points on earth eg GPS.(Advantages)
-Good for very long distances
(Disadvantages)
-Very expensive
- 55(Network Interface Card) & (Network Access Point)Devices using wireless networking need a NIC.
Network Interface Card.
It`s the hardware for receiving wireless signals.
It`s built-into modern devices eg tablets & Phones.
The NIC connects to a NAP.
Network Access Point.
Lots of places offer NAP`s, such as cafes & Libraries. - 56Hypertext Markup Language (HTML)HTML is made up of tags, mostly in pairs. Pairs of tags are called HTML elements.
The open tag is written between <>
Most tags also have a close tag which includes a forward slash. text - 57LINKhttp://www.thuto.org/ubh/web/html/tags1.htm
- 58Client Side Processing
- 59Server Side Processing
- 60Client Side Processing Client side is viewing web pages on your client device(Advantages)
Speed-Processing is faster on the client because data does not travel back to the server across the internet.
Security-Data can not be intercepted on the client in the same way it can be when data is transmitted back to the server across the internet. - 61Client Side Processing (Disadvantages)(Disadvantages)
Browser Specific- A web developer can not be sure how their website will appear on a screen on the client side.
Computer Speed- The web developer has to relaying on the speed of the client computer to deliver the interactive features, so if that is slow then the processing will be slow. - 62Server Side Processing (Advantages)Servers are Powerful Machines- A web server is likely to be way more powerful than a client computer, so it can process data faster.
No Browser involved- Servers don`t use browsers so there are none of the difficulties you get on the client with different brands.
Efficient- Everything is done on the server, so no need to wait for downloads etc. - 63Types Of Relationships
- 64DATABASEA Database is a structured collection of data.
- 65TABLEA Table stores a lot of data e.g details of all students in the school.
- 66FIELDA Field are the columns in a table eg forename, surname, gender, date of birth.
- 67RECORDA Record is one row that stores data about a single item eg a student`s details.
- 68PRIMARY KEYThe Primary Key is a special field with a unique identifier eg a student ID.
- 69FOREIGN KEYThis supplier ID is not really product data.
So it`s called a Foreign Key.
Its purpose is to link to the supplier table. - 70RELATIONSHIPMost databases need more than one table to store all data
So the tables need to be linked (or "related") to create a relational database... - 71DATA TYPES AND USES: TEXTAny kind of characters, including letters & numbers eg LA6 2HJ.
- 72NUMERICNumeric values eg 1.5
- 73DATA/TIMEDates and time eg 01/04/2014
- 74BOOLEANOne of two values, such as Yes/No or True/False Yes
- 75Online and local Databaserrt
- 76Threats To Data
- 77How To Protect Data
- 78OpportunistA company`s network security can be breached by people who take a random opportunity, such as an unattended PC
- 79VIRUSViruses are malicious programs designed to replicate and spread across a computer or a network to damage or corrupt files & data.
- 80MalwareMalware is the name for several other types of malicious software, such as Trojans, worms, adware, spyware and other nasty software that aims to cause damage to files or to steal data.
- 81PhishingMeans when hackers use fake emails or fake websites to trick people into clicking links and then entering their personal data, such as banks passwords.
- 82Accidental DamageThis include floods, or fire or hurricanes or damage from untrained users.
- 83Hackersmeans people who purposefully try to gain authorized access to a computer or a network. But bear in mind that a high proportion of hackers are people who actually work for an organisation.
- 84Data Protection Act 1998Provides 8 principles that govern the way data about individuals is stored and used.
- 85Computer Misuse Act 1990Introduced to protect from hackers and malicious use of viruses.
- 86Copyright, Designs and patents Act 1988protects creators of original works.
- 87Freedom of Information Act 2000Provides individual the right to see information stored about them. Data can also be accessed about public bodies.
- 88TECHNOLOGY CCTVCCTV`s cameras track your record movements.
- 89GPS DEVICESGPS in phones tracks your location.
- 90Airport Passenger ListsTravel Data like Airport Passenger Lists
- 91COMMUNICATION Monitoring EmailAuthorities monitoring emails & web
- 92Monitoring Web Sites VisitedSearch Engines logging your keywords.
- 93Logging Keywords Typed into Search enginesSites using cookies to track Browsing.
- 94Components of Email AddressUser name of the component of the email address.
- 95Pay-per-click advertisingDisadvantages:
Time consuming to monitor traffic which delays the refinement of keywords.
Competition for keywords which could mean that the company is at the bottom of the search page.
Vague use of keywords means that although people click to find out what is advertising. - 96FIREWALLAdvantages:
It monitors all data arriving from the internet so that it can stop/block anything it considers harmful.
Checks IP addresses/packet which are compared against a database. - 97Two factors that the school need to consider when backing up its data -Full back up all the data backed up every time the systems runs. -Types of back up full back/incremental/differential.Two reasons why a high bandwidth is important when using the internet.