Topic vs. Heading

Difference Between Topic and Heading
Topicadjective
Topical.
Headingverb
present participle of head
Topicnoun
Subject; theme; a category or general area of interest.
A society where a topic cannot be discussed, does not have free speech.Headingnoun
The title or topic of a document, article, chapter, or of a section thereof.
Topicnoun
(Internet) Discussion thread.
Headingnoun
(nautical) The direction into which a seagoing or airborne vessel's bow is pointing (apparent heading) and/or the direction into which it is actually moving relative to the ground (true heading)
Topicnoun
(obsolete) An argument or reason.
Headingnoun
Material for the heads of casks, barrels, etc.
Topicnoun
An external local application or remedy, such as a plaster, a blister, etc.
Headingnoun
(mining) A gallery, drift, or adit in a mine; also, the end of a drift or gallery; the vein above a drift.
Topicnoun
the subject matter of a conversation or discussion;
he didn't want to discuss that subjectit was a very sensitive topichis letters were always on the theme of loveHeadingnoun
(sewing) The extension of a line ruffling above the line of stitch.
Topicnoun
some situation or event that is thought about;
he kept drifting off the topiche had been thinking about the subject for several yearsit is a matter for the policeHeadingnoun
(masonry) The end of a stone or brick which is presented outward.
Headingnoun
a line of text serving to indicate what the passage below it is about;
the heading seemed to have little to do with the textHeadingnoun
the direction or path along which something moves or along which it lies
Headingnoun
a horizontal (or nearly horizontal) passageway in a mine;
they dug a drift parallel with the vein