By now most likely you have realized that thin client refers to wireless Internet applications. We call this type of application "thin client" because no software is required on the wireless device except for an Internet browser. The browser accepts a markup language, parses it, and displays it to the application user. Any response from the user is sent back to the server, where it can be handled appropriately. For true thin client applications, all of the application logic resides and is executed on the server platform. Hence, the client does not require much processing power or memory to be able to run these types of applications, making them suitable for very small, resource-constrained devices.
Keep in mind that thin client applications are not limited to cell phones. Many devices on the market support thin client applications. Actually, any device that has a microbrowser and a wireless connection is suitable. This includes laptops, PDAs, smart phones, and cell phones, among other more specialized devices.
This chapter gives an overview of the thin client application architecture by highlighting the main components that comprise a successful solution. Following the architecture overview, we take an in-depth look at one of the leading wireless Internet protocols, WAP.