Oxadiazole is a related term of oxazole.

In organic compound terms the difference between oxazole and oxadiazole

is that oxazole is a five-membered heterocycle having three carbon atoms, one oxygen atom, one nitrogen atom and two double bonds; the 1,3- isomer is aromatic while oxadiazole is any five-membered heterocycle having two carbon atoms, two nitrogen atoms, one oxygen atom, and two double bonds.