What do ppc and pps short messages mean?

In fact, you know it on Baidu Encyclopedia, which is very detailed.

Prepaid service is a new service of mobile communication intelligent network based on ETSI GSM CAMEL2 standard. Users who use this service need to deposit some money in their accounts first. When a prepaid service user makes or answers a call, the mobile intelligent network system will judge whether the user has the right to make a call and whether the amount in the user's account can make a call. During the call, the system charges the call in real time and modifies the amount prepaid by the user in real time. When the user is short of money during the call, the system plays the corresponding recorded notice to the user and terminates the call within the specified time. China Mobile's "Shenzhouxing" business is a typical PPS business. At the same time, there is the new power package of China Unicom, which is also a typical PPS business.

PPC refers to PDA using Microsoft Windows Mobile Professional series operating system. The earliest Windows Mobile operating system was PocketePC1.0, which was not very successful, but PPC was named after it. Subsequently, Poceket PC 2002, Windows Mobile 2003 and Windows Mobile 2003 SE were all very successful operating systems. The latest Pocket PC operating system is Windows Mobile 6.5(Windows Phone is a smartphone operating system, not PPC).