A Web Application (or INTERnet Web Application) is a database that allows users (whether staff or customers) to interact with the database from anywhere on the internet. These types of databases are well-suited for internet commerce, or any application in which you want your customer to be able to interact with your services using the convenience of the internet.
INTERnet web applications can help expediate business, by automating processes. For instance, an online order can check inventory before processing the order, adjust the inventory after processing the order, and send an e-mail to the warehouse to ship the product. This reduces the amount of paperwork, the time from order to delivery, and the chance for human error.
The great stength of INTERnet web applications is that they allow anyone in the world with access to the internet the ability to interact with your database, regardless of their their choice of computers and/or operating systems. This concept is called cross platform programming