1.3.4 Web Technologies

Question 1

Describe the client-server model

Answer 1

• Servers: provides resources, e.g. web page
  
  • The server hosts sites
  • The server process is associated with a computer port
  • A server sends the required resources in response to a request
• Client: the service making the request, e.g. a browser
  
  • The client process makes the request and waits for a response

Question 2

Describe client-side processing

Answer 2

• Refers to operations carried out on the ‘client’ side of a client-server relationship
  
  • A browser will format a web page by the HTML and CSS tags/styles sent by the server
  • Operations are carried out to offload processing from the server, reducing load and communication bandwidth

Question 3

Describe server-side processing

Answer 3

• Refers to processing done on the ‘server’ side of a client-server relationship
  
  • Web pages containing data from file systems sends the client customised pages
  • A resource requiring server-side processing uses a server-side script

Question 4

Describe how a PHP interpreter will handle a dynamic server-side request

Answer 4

• The server-side script will execute an SQL statement
  
  • Dynamically creating an HTML page from a database
• The HTML is then returned to the client web browser with a success status code

Question 5

What does the ‘thickness’ of a client computer represent?

Answer 5

This is the level of processing and storage that the client does in comparison to the connected server

Question 6

What is the difference between thin-client and thick-client computing?

Answer 6

Thin-client: server performs more processing and storage

Thick-client: client performs more processing and storage

Question 7

What is an API?

Answer 7

Application Programming Interface:

A set of protocols on how applications should interact

Sets out the format of communication in client-server relationships