Web archives and the Wayback machine

The wayback machine is a website that provides an old snapshot of a website.  The websites typically cached are generally more popular websites such as google or wikipedia.

http://web.archive.org/web/19981202230410/http://www.google.com

I looked up google and the date of this snapshot is 2nd December 1998

Introducing CSS

CSS (Cascading Style Sheets) is used in conjunction with HTML to create easier to edit webpages.  It makes it easy to create global definitions for doing many things, such as text size, colour and font just by changing a class.

Tim Berners-Lee is a co-creator for W3C (World Wide Web Consortium)  He also wrote the first browser, set up the first web server and created the standards for HTTP and HTML.

The W3C created standards for CSS.  By creating standards they got rid of the issues of privatization instead they let others create software that would conform to their specifications.  Fortunately for them, almost all web browsers support CSS and many HTML/Webpage editors also support it.

Web Acronyms

Acronym	Definition
URL	Universal Resoure Location, is generally entered into address bar to navigate to webpages
FTP	File Transfer Protocol, is generally used for uploading to remote web servers
HTML	HyperText Markup Language, used for displaying web content.
ISP	Internet Service Provider.
ADSL	Asymmetric Digital Subscriber line.  Uses frequencies not used by voices to speed up connections over copper cable lines.
JPEG	Joint Photographers Expert Group.  An extremely common file format for images.  One of 3 formats supported for web images.
GIF	Graphics Interchange Format.  A common format for moving images.  Typically low quality and one of 3 formats supported for web images.
PNG	Portable Network Graphic.  A common format for images.  It supports transparency.  One of 3 formats supported for web images.
CMS	Content Management System.  Makes it easier to edit web pages that are updated frequently.  Especially useful for blogs and for displaying RSS feeds.
FAQ	Frequently Asked Questions.  Provides answers to questions asked frequently
P2P	Peer to Peer.  Typically used for downloading large, popular files using a peer to peer client such as bittorrent or utorrent.
PDF	Portable Document Format.  Very common format for business documents and digital manuals requiring graphics.

How a browser gets a webpage

Almost all decent browsers have an address bar so users can easily type a web address in and navigate to that webpage.

But how does the browser know which page to get and where to get it from?

When an address (URL) is typed in and Enter is pressed  the browser sends out a request  looking something like "https://www.google.com.au/".

Breaking this down gives an overview of what does what.

"https://"	Called a scheme, gives information on how to connect eg. ftp,http or https.
"www.google.com.au"	This is called the host, it can either be an IP address (72.14.207.99) or can go through a DNS server that resolves "www.google.com.au" as having the IP 72.14.207.99 It gives information on where to connect.

The host can also have a port specified by having a ":" after the IP/Domain name.  Web server ports are usually configured for port 80 as a standard.

After the host/port ther is one last thing, the path of the resource eg. "http://en.wikipedia.org/wiki/Domain_name" where "/wiki/Domain_name" is the path to the selected resource.

So for a browser to get a webpage it sends out a request to the DNS server for a particular URL, the DNS will then resolve the IP of the web server and communicate this back to the browser.  The browser then sends a request to a server running on that IP then the server responds with the requested information from the requested directory on the server.
The browser then interprets these packets of information and displays a webpage on the screen

Web 2.0

Web 2.0 describes web sites that use technology beyond the static pages of earlier web sites. The term was coined in 1999 by Darcy DiNucci

The distinctions between Web1.0 and Web 2.0 are the accessability and edibility for all.

Web 1.0 - Only editable by a certain small group of people

Web 2.0 - Editable by all,however only a small number actually edit

An example of Web 2.0 is the same information (this post) shared over multiple sites

Source - Britannica Online, Wikipedia

Internet Graphics

There are 3 types of image files that work in HTML.  These are JPEGs, PNGs and GIFs (according to the creator, pronounced 'jif").

JPEG	Joint Photographic Experts Group High compression Lossy No animation No transparancy Main Advantage - Mostly for photographs and realistic images Main Disadvantage - Lossy compression
PNG	Portable Network Graphic Supports transparancy No loss compression No animation Main Advantage - Mostly for straight lines, text heavy images and few colours Main Disadvantage - Large filesize
GIF	Graphics Interchange Format Supports transparency No loss compression Supports animation Main Advantage - For moving pictures Main Disadvantage - Only 8bit colour palette

World Wide Web

The web was developed between March 1989 and December 1990. The main name behind the web was Tim Berners-Lee

External objects including pictures and extra code are all referenced using what are called 'tags'. The components of a website all reside in its code, image tags, links etc. all are using the code

A web server is used for hosting a website on a particular IP address which anything can connect to. A web browser is what connects to this server, in modern times we type in a URL instead of an IP address, this URL would have been linked to a particular IP address via a DNS server and so will connect automatically.