A vinyl compound (formula −CH=CH2) is any organic compound that contains a vinyl group (Preferred IUPAC name ethenyl), which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group. An industrially important example is vinyl chloride, precursor to PVC, a plastic commonly known as "vinyl".
Vinyl groups are alkene derivatives: Primary alkenes contain vinyl groups. On a carbon skeleton, sp2-hybridized carbons or positions are often called vinylic. Allyls, acrylates and styrenics contain vinyl groups. (A styrenic crosslinker with two vinyl groups is called divinyl benzene.)