Section 5 Network And Web Technologies Flashcards
The importance of protocols?
protocols: set of rules defining common methods of data communication standardised across all devices
What is TCPIP
A protocol stack
TCPIP layers
application
transport
internet
link
Application layer?
uses HTTP, POP3, FTP - protocols relating to the application being used to transmit data across a network
transport layer?
uses TCP (UDP is slower and lossy) to establish an end to end connection
data split into packets and labelled with packet no., total no. of packets and the port number through which it should route
this layer requests retransmission of missing packets
reciept of packets is acknowledged
internet layer?
adds source and destination ip addresses
routers operate on this layer
use this ip address to forward the packet elsewhere
what does a socket specify?
the device which the packet must be sent to and the application being used on that device
link layer?
physical connection between network nodes and adds the MAC (media access control) addresses identifying the NICS (network interface cards) of the source and destination computers so the right hardware can be located
HTML
Hypertext markup language
CSS
Cascade style sheets
use of HTML
script that web pages are written in
describe content and structure of a web page
so a browser can interpret and render the page for the viewer
use of CSS
describes the style and layout of a page
includes changing colours and fonts
what is this a pair of?
<html> and </html>
tags
<html> definition
</html>
all code enclosed is interpreted as HTML
<body> definition
</body>
defines the content in the main browser content area
