L5 The World Wide Web Flashcards
WWW webpage, website etc. URL (domain, path on server, resource) HTTP, HTTPS Proxy, Cache, Firewall Search engines Filter bubble
What is Multimedia?
The integration of many forms of
media (text, video, sound, images etc)
What is Hypermedia?
The creation of links between
multimedia content
When and how did WWW (the world wide web) start?
Tim Berners-Lee built the first website in 1991 at CERN
In June 1993, Mosaic was released, it’s the first widely used web browser. By October 1993, there were 500 web servers around the world. By this point, Berners-Lee realized the WWW had to be freely available so he convinced CERN to make the source code public. In 1994, Berners-Lee established the World Wide Web Consortium (W3C), which creates standards for the WWW
What is a web browser?
Application software used to access content
What is a web server?
A computer with software that makes files available on the WWW
What are the 3 components of URLs?
https://www.cs.auckland.ac.nz/~andrew/teaching.html
Protocol: https
(Other common protocols: ftp, http)
Domain: www.cs.auckland.ac.nz
(Can be a domain name or an IP address)
Path on server: /~andrew/
(Resource: teaching.html)
What is HTTP?
HyperText Transfer Protocol; used by web browsers to request resources (e.g. webpages, images, sounds) from a web server
a method for encoding and transporting information between a client (such as a web browser) and a web server. HTTP is the primary protocol for transmission of information across the internet. Information is exchanged between clients and servers in the form of hypertext documents, from which HTTP gets its name.
What is HTTPS?
HyperText Transfer Protocol Secure
Encrypts the HTTP connection using TLS (Transport Layer Security)
Becoming essential for websites to use HTTPS to keep user information secure (eg. when banking online)
What are the other 3 parts of WWW?
Proxy
Cache
Firewall
What is proxy?
Proxy: sits between client and server so it can intercept and process requests
(one use of proxy is to filter out the content)
A proxy server is a system or router that provides a gateway between users and the internet. Therefore, it helps prevent cyber attackers from entering a private network. It is a server, referred to as an “intermediary” because it goes between end-users and the web pages they visit online.
What is cache?
stores recently requested resources so they can be accessed quickly
A proxy can use a cache to store recent requests, enabling it to process requests faster
(When a user visits a website for the first time, its content might not be stored in the cache, so it’s fetched from the main server. Once fetched, it’s stored locally. When the same website is requested again, it’s retrieved from the cache, speeding up the process, reducing delays, and saving bandwidth.)
What is a firewall?
: prevents unauthorized access to a private network
a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules.
What are search engines?
A website that helps a user to search for information on the WWW
What is indexing?
organizing data so that it is easier to search
How do search engines work?
Most search engines will have programs, these are known as robots or spiders, they will go into the web and index web pages, build a database then when users search with a keyword, the search engine will use that keyword to pass through the database and provide the user with the results.
