Web technology overview

With the figure you can have an idea of how is the architecture of the Web Applications.

We highlight:

• Client-Server architecture
  • Server: stores the data and processes the core application
  • Client: the browser renders the graphical part a.k.a. GUI: Graphical User Interface
• Native applications (compiled) are faster in execution than scripts (interpreted by another intermediate application such as Apache).
• Web 1.0 paradigm just uses HTML (Hypertext Markup Language) in client-side (server uses several programming languages as Perl or PHP).
• With Web 2.0 come the RIA: Rich Internet Applications, using AJAX technologies in client-side.
• AJAX is a group of technologies that means Asynchronous Javascript and XML. Makes the client possible rich GUI applications.
• PHP scripting language means PHP Hypertext Preprocessor (recursive definition)
• Web applications (server-side) use to communicate to the MySQL database to store data (red line).
• Client access to web applications via port 80 of the network (blue line).
• Web server applications:
  • Apache: free software web server, the more used in all the world web servers.
  • IIS: Internet Information Server (Microsfot). Supports ASP.NET advanced language.
  • Lighttpd: (pronunced lighty) last-generation web server used in servers with high load.
• 2 paradigms of server-side web applications:
  • Script-based: Apache (web server app) executes the scripts in PHP, CGI, etc.
  • Stand-alone: applications that doesn't need a web server. The usual example are applications using Python using Django framework (need a Python interpreter though). Google products are based in that technology and have better security than Apache or IIS based ones.