The N, Z, C, and V bits are the condition code flags. You can set them by arithmetic and logical operations, and also by MSR and LDM instructions. The processor tests these flags to determine whether to execute an instruction.

In ARM state, you can execute most instructions conditionally on the state of the N, Z, C, and V bits. In Thumb state, you can execute fewer instructions conditionally. However, you can make most instructions conditional with the IT instruction.

See the ARM Architecture Reference Manual for more information about conditional executions.