[linux-dvb] question about definition of section in PSI of Transport stream

[loody]

Dear all:
I am reading iso13818-1 right now.
But I cannot figure out what the section mean in PSI.

In PAT, there is a N loop tell us how many programs in this TS and the
corresponding pid of PMT.
Is section equivalent to program?
Suppose there is 10 loop in PAT, and there will be 10 sections, right?

thanks for your help,
miloody