There are three means of understanding the regulation and one additional means of viewing how it has been applied in the past. In order of significance; the first method is to review the preambles to the Federal Register, where the regulation (or changes to it) were published. These preambles include an explanation as to the reasons for the regulation and how it was crafted. The second source after the Federal Register preambles are the FAA Chief Legal Counsel letters of interpretation. The authority for the regulation and it's application and interpretation rests with the FAA Administrator, and the Administrator authorizes (delegates) the Chief and regional legal counsel to issue interpretations of the regulation. These are searchable online. The final method is reading the regulation itself.
A fourth method is to review cases adjudicated by administrative law judges, rendering the specific application in a specific case, but those do not set precedent, nor do they interpret the regulation. They simply provide some insight into how it was applied in a specific case.
An example of a Chief Legal Counsel interpretation applicable to your case is Durden, 2014. It answers the question regarding what is meant by "operations under this part," among other things, as it relates to the 1000 hour requirement of 14 CFR 121.436:
https://www.faa.gov/about/office_org...rpretation.pdf
Chief Legal Counsel interpretations (search):
https://www.faa.gov/about/office_org...interpretation.
Federal Register (search):
https://www.federalregister.gov
Title 14, Code of Federal REgulations (search):
https://www.ecfr.gov/current/title-14