What is a client in the context of a PDA? A client is a name for a Pocket PC PDA application on a wired or wireless network. Clients come in two varieties, Thick and Thin. "Thick clients" are generally the full Pocket PC operating system with a database application on it which is fully functional offline.
A "thin client" is a network device (Pocket PC) that relies on servers for applications, data storage, and administration. In other words, it most often uses a web browser on the Pocket PC to connect to the data source.
Which of these architectures are better? I believe having a database on the Pocket PC is best for most situations. Why? If you have no connection or a bad wireless connection, your software application can continue to function normally and later you can synchronize. This allows you to continue working and documenting your work on your Pocket PC with or without a good wireless connection.
If you are using a "thin client" or web browser interface into your database back at the office, then if you lose that connection you have no application. Without your online application, you risk not being able to do your job, provide poor customer service, and wasted time and expenses.
Intel, on their Mobilized Software website strongly advocates an architecture that allows you to continue working with or without a connection to a server.
In addition to the connectivity issues, a Pocket PC user often wants their software application to interface with many different hardware add-ons such as GPS, RFID, Bar code scanners, automobile black boxes, digital thermometers, surveying equipment, and much more. These add-on accessories can easily be integrated with a "thick client" that has a framework that supports third party data capture accessories. A thin client browser is not set-up to handled this environment and limits your ability to take advantage of these convergent devices.