If you're new to Web application development, you need to become familiar with a few key concepts before you begin developing your sites.

Databases
A database is used to store structured data. Data in a database can commonly be thought of in terms of a grid, organized into rows and columns. Each column has a particular type of data associated with it (for example a customer's first name, or zip code), and each row makes up a unique record of information. Most databases are called "relational databases" because the data in different tables can be linked together with different types of relationships. For web applications, databases are used to store some of the content needed for the application (customer contact information, for example). Popular databases include Microsoft Access and SQL Server, Oracle, IBM DB2, and mySQL. For more information about the databases you can use with Dreamweaver UltraDev and your application server, see Databases.

Application Servers
A Web application server executes the pages built with Dreamweaver UltraDev, then delivers them to a web browser. As part of this process, the application server reads all the server side code on the page and translates it into html to be delivered to the browser. This process usually includes connecting to a database to obtain data necessary on the page. Advanced application servers can perform more sophisticated tasks like keeping track of individual users, and connecting to other sources of dynamic data.

A number of different application server technologies are available for building dynamic sites that connect to databases. Using UltraDev, you can build pages for ColdFusion, Active Server Pages (ASP), JavaServer Pages (JSP) application servers. To find out more about the application servers you can use with Dreamweaver UltraDev, see About Application Servers.

Application Files
The last piece of the puzzle necessary to create a dynamic application is the actual application files. You use UltraDev to create these files, which actually contain the mixture of html and application logic that controls the application. UltraDev is used to speed the creation of these pages using familiar visual paradigms. Unlike html, however, these files are written for a specific type of application server (ColdFusion, for example). Typical file formats used today include .jsp (JavaServer Pages), .cfm (ColdFusion Markup), and ASP (Active Server Pages).

The database and application server work together to deliver dynamic content from a server to a site visitor's web browser.