Allylic carbons are sp³ hybridized; vinylic carbons are sp² hybridized.
The site of the saturated carbon atom, where the vinyl group attaches (e.g. next to the OH in allyl alcohol) is called the allylic position or allylic site. A group, such as -OH, attached at an allylic site is sometimes described as allylic. Two examples of simple allyl compounds are allyl chloride and allyl alcohol.
Substituted versions of the above, such as the trans-but-2-en-1-yl or crotyl group (CH3CH=CH-CH2-) may be also referred to as allylic groups.