Tuesday 27 September 2011

Everything Computing

Internet- A global networks of networks which breaks down information in to packets, and sends them from computer to computer.

Web- The web covers the structure of the HTML with texts, graphics and images etc.

Intranet- This is a private server that only allows certain websites to be allowed and breaks off other sites like youtbe.

Extranet- The JOG's jogle can be only be opened by people who study or work at the school which they have their own login and password.

Packets- Packets are breaken down from huge files that seprates and flys across the internet, when they get to there destation they are numbered so they appear like they would on the computer it got transfered from.
The packets may get damaged along the way so they get scanned by the server for viruses.

Router- Routes the information to another router that tells that to go to another one had gives the packet a rough direction of where to go to the right computer and there billions across the world revicing and directing the packets.

Domain Name- Something that we can understand like http://www.google.com/


IP Address- A custom address that is unqiue to the computer the router checks around the area to see if any other computer has the same IP if this happens both computers will get eachothers information and will conflict and crash.

Domain Name Server (DNS)- changes our Domain names that we can under stand into IP adress'es.

Registrars- Manages the allocation of the domain names, and makes sure it isn't doubled.

 Internet Registries- Manages allication and blocks certain domain names.

ISP- Simply stands for Internet Service Provider. Take BT they provide an individual internet port for you to use.

URI- porvides an unique identity
URL-Unqiue location for something but cannot be found.
URN- The unqiue name for something.
FQDN-This stands for Fully Quailifed Domain Name for example it includes the "www" http://www.google.com/

URL Structure-
Protocol- Provides the HTTP
Domain- The actaul the name.
Path- is the books.
Resource- The type of file PDF.

http://www.library.com/books/rj.pdf

Operating systems is what runs off the physical hardware to process information and run essential programs

 Library systems are for software used to catalog, track and inventory a library's assets. Also is used for printing programs
Utility runs background programs eg like AVG to check for virus and it only pops when a virus is in the system
 
General Purpose software means it can do multiple tasks, for example a word processor (Microsoft Word) which can be used for word, spread sheets, online documents etc.
 
Special Purpose software is a program that spicily runs something like a web browser, itunes and  Mp3 (Mp4a)
Bespoke is a program specially made for a company, sometimes they pay millions or billions for this program made by programing experts. Or if your company is IT heavy they can hired inside their company, and less the cost. Examples are Air Traffic Control, CCTV and Police tags.


Input: A piece of equipment that is used to get data in to a computer
Output: A piece of equipment used to get the computers work to the outside world to get viewed
input devices.
Optical mouse- uses a infared light to bonce the light off the surface to move the mouse cursor on the computer screen.

graphic tablet- When the pen touches the first layer pf glass on the tablet it presses dwon to the second layer, this is deceted by a sensor to make a contact, to show where the pen is.

smart card reader- used to read yout pin on your card to verifiy the sercuity.

Bar code reader- used to scan a item to pick it up on the database and display a price etc.

Digital Still/ Video camera- they can film and capture images (still or in fps)

Voice Recognition- picks up vibrations in the air

Out Put Devices

Cathode Ray Tube- these are the old monitors with a charge to kill you when its off, also has higher res than a LCD screen

Flat Screen LCD- This liquid Crystal Display uses less power than teh CRT monitors but has lower res than the CRT.

Plasma Screen- Plasma screens are ture HD Display
Ionized gases such as the ones shown here are confined to millions of tiny individual cells across the face of a plasma display, to collectively form a visual image
ink jet and laser printers- Ink jet printers sprays hot ink on to the paper to build a image, it may be slower but it products very high quality images
Laser printers- Laser printer are primary used in work offices because they are quick to print off mass amount of work docements, they can product pictures but at lower res.

Out Put Devices- Speakers- They pick you the sound files on the PC and vibrates to the right pitch.

Primary is memory being used whilst the computer is on (RAM)
Secondary is where you can save and store music, videos and programs 
Bit- Smallest unit 0-1
Byte 8-Bit
Kilobyte- 1000 bytes (1024)
Megabyte- One Million
Giga byte- One billion
Terabyte- One Trillion

secondary storage
CD ROMS
HD Disks
Blu Ray disks
USB
Memory Card

TCP- Transmission Control Protocol
IP- Interent Protocol
These two are used to make packets get to your computer without hassel

1 comment:

  1. Very good - I think you could also do with a summary of the four layers of the TCPIP stack

    ReplyDelete