exam review module 9

Question 1

servers

DNS servers

Answer 1

computers that respond to requests for address lookups

ex: computer sends DNS server the name (website link) - it looks it up in a data base and returns with 129.97.167.19.

Question 2

web server

Answer 2

a computer with the name www.student.cs.uwaterloo.ca with the address

129.97.179.19.

Question 3

clients

Answer 3

the client = web browser running on a different computer than the web server.

¥ The same requests can be made for images <img></img>, which are also hosted on web servers.

¥ Modern webpages have dozens of additional references (HTML requests)

Question 4

web servers role

Answer 4

response to HTTP requests and provide files

Question 5

clients role

Answer 5

requests files via HTTP, interpret HTML files and make additional requests, display HTM: files properly

Question 6

static web pages

Answer 6

Static = Does not change

if the code gets changed manually its a static page

Question 7

dynamic web pages

Answer 7

Changes over time

A web page is dynamic if it automatically changes its content due to its “environment”.

Question 8

server side dynamic web pages

also VLOOKUP relation

Answer 8

web pages that are changed dynamically by the web server

instead of simply fetching a web page, the web server could generate one.

Google search is like a very advanced version of Excel’s VLOOKUP function.

VLOOKUP is similar to Amazon -> provides dynamic web pages.

Question 9

client side dynamic web pages

Answer 9

pages modified by the web browser

Question 10

javascript

Answer 10

the web interprets and executes the code

• used for many applications, but works well for manipulating web pages.

javascript always begins with

Question 11

cookies

Answer 11

how the web tracks your behaviour

when an HTTP request is amde, thr web server can send back a message to the client in addition to the web page

They increase the convenience of the web by remembering who you are and your credentials.

They can also be used for bad purposes, as web servers can identify you and send you unwanted ads.

Question 12

query strings

Answer 12

Everything that appears after the ? is known as the query string.

A query string is made up of pairs of values, with

Each pair is separated by an ampersand (&)

The two values within the pair are separated by an equal sign (=)

ex:
http: //x.com/content?session=878d294f0d35&referral=alice&sound=off&course=cs100&page=3&auth=175b929384e06e4742930fd69133cf6c

Question 13

variable weights

Answer 13

prioritize results list first, followed by answers list.

var weights = [
[[q1a1r1, q1a1r2, q1a1r3, … q1a1r?], [q1a2r1, q1a2r2, …], [q1a?s1, …]],
[[q2a1r1, q2a1r2, …], [q2a2r1, …], [q2a?r1, …]],
…
[[q?a1r1, q?a1r2, …], [q?a2r1, …], [q?a?r1, …]]

Q1A1R1, Q1A1R2, Q1A1R3, Q1A1R4,
Q1A2R1, Q1A2,R2, Q1A2R3, Q1A2R4,
Q1A3R1,Q1A3R2,Q1A3R3, Q1A3R4,
Q1A4R1,Q1A4,R2,Q1A4R3, Q1A4R4

Q2A1R1,Q2A1R2, Q2A1R3, Q2A1R4
Q2A2R1,Q2A2R2, Q2A2R3, Q2A2R4
Q2A3R1,Q2A3,R2,Q2A3R3, Q2A3R4
Q2A4R1,Q2A4,R2,Q2A4R3, Q2A4R4