The only 'section' field I am aware of is in mdl_course_sections.
mdl_course_sections has several fields:
- id - the unique id of the section (i.e. section 2 in two different courses will have a different id here)
- course - the course the section belongs to
- section - the section position within the course (0, 1, 2, 3, etc. for each course) (i.e. if there is a 2nd section in multiple courses, then all of them will have a 2 here).
- sequence - ordered, comma-separated list of ids for the mdl_course_modules table, the activities that are present in that course section