Question about affect of cpulimit

This is more of question rather than a problem.
When I use cpulimit -l 20 with a program/script, how will this affect the programs/scripts that are called/run by the original program/script? If prog A run prog B which in turn runs prog C, does the cpulimit -l 20 only affect prog A or will it affect all the program prog A will all and its children?

Thanks.