Communication and Internet Technology

Communication and Internet Technology

1. Hardware

2. Server side scripting

   • Uses PHP
     • Happens at the server side
     • Uses a software called Apache
     • Why use server side scripting?
       • More security
       • Better performance
     • PHP is executed on the server, the codes are not sent to the user, only its results are

3. Client Side Scripting

   • Happens at the client side (browser)
     • Browser looks at the tags and fetch the images, videos, javascripts...
   • Uses Javascript

4. Communicaiton Types

   • Parallel
     • Uses more than one communication line at a time to transmit more than one bit of information at a tiem
     • Example: Buses in the computer that connect to the motherboard
   • Serial
     • Communcation that uses only one transmission line to send one bit of information at a time
       • Example: Peripheral computer devices such as mouse,keyboards etc.
   • Simplex
   • Half duplex and full duplex
   • Client-Server Model
     • Thin Client Server Model
     • Thick Client Server Model
   • Synchronous
     • Asynchronous
       • Asynchronous transmission is when the two computers' clocks are not synced together
         • start bits and stop bits will need to be sent in order for the two computers to communicate
     • Communication when both computers' system clock are in time with each other and information can be sent immdiately with real time response

5. Web RequestLife Cycle

   • 5 layers Internet Suite Stack
     • Application
       • Transport
         • Network
           • Data Link
             • Physical
           • Reroutes the data to its destination
         • Transport layer converts the URL into IP address using a DNS and passes this on to the next layer
       • Browser sends the URL off to the Transport layer

6. IP Addressing

   • Public
     • Static
       • Normally assigned to web hosts or servers
       • Does not change
     • Dynamic
       • Users/Clients only
       • Changes whenever a user disconnects and reconnects
   • Private IP
     • Used in LANs, always Static