What are some of the characteristics of the ARM processor?

What are some of the characteristics of the ARM processor?
http://www.siliconray.com/development-boards/arm.html
ARM have seven the operating mode: user mode, rapid interrupt mode, external interrupt mode, the mode of management, the data access to suspend mode, not defined instruction to suspend mode, system model. In addition to the user mode, the other six are privilege mode. The model of the processor can through to switch control, but can be by external interrupt or exception processing in switching. Most users to run the program in user mode, at this time, applications can't access by some of the operating system protection systems, applications can't directly processor mode switch. When the need for the processor when switching mode, the application can produce exception handling, in the exception handling of processor switching mode.
The mode of operation is not all CPU, MUP processing unit has dormancy, such as thumb work mode; Privilege don't know you what is meant by a; Mode is through the control registers to change, is by the software control!