There are different parts of a CFR section (aka federal regulation or federal rule) such as the citation, title, chapter, part, section, section title, etc.
The commercial services (Westlaw, Lexis, CCH) have annotations to help with your research, so always use an annotated version of the CFR, if available.
Annotated versions give you:
Westlaw Example - 8 C.F.R. 312.1
Research Annotations
Westlaw gives you all the cases, other regulations, agency decisions, secondary sources, etc. that cite your regulation.
e-CFR Example - 8 C.F.R. 312.1
Westlaw Example - 8 C.F.R. 312.1
Annotated versions give you: