Allyl halides are those compounds in which the halogen atom is bonded to sp3 hybridised carbon atom next to carbon-carbon-double bond e.g:
CH2=CH−CH2X and CH3CH=CHC(Br)(CH3)2
The compounds in which the halogen atom is bonded to the sp 2 hybridised carbon atom of an aromatic ring are aryl halides.
The compounds in which the halogen atom is bonded to the sp 2 hybridised carbon atom of a carbon-carbon double bond are vinyl halides.
e.g., CH2=CH−X
The compounds in which the halogen atom is bonded to the sp3 hybridised carbon atom which is further bonded with two alkyl groups and one hydrogen atom are secondary alkyl halides.