Examples why they are 2 different things

Well, what do you think of this though: the following four Science links about undecylenic acid and miconazole describe these two molecules as very different from each other:

This first link says that the action of Miconazole is it "inhibits the biological production of ergosterol, a molecule needed by fungi to build their cell walls"
And the second link states that although undecylenic acid is antifungal, its method of action is unknown. So since Science knows the method of antifungal action of Miconazole, but does not know the method of antifungal action of undecylenic acid, they are different.

In the third and fourth links, the exact chemical formula (a series of letters and numbers that indicate exact molecules to chemists)of these two molecules are given - and they are not the same:

http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_ARTICL...


http://en.wikipedia.org/wiki/Undecylenic_acid


http://www.cas.org/motw/miconazole.html


http://www.bikudo.com/product_search/details/172394/undecylenic_acid.html