Allyl carbocation : \((CH_2=CH-\overset{\oplus}CH_2)\)
When positive charge is present on the allylic carbon of the allyl group, the carbocation is known as allyl carbocation.
Allyl carbocations are more stable than alkyl carbocations due to resonance.
Stability of primary, secondary and tertiary allyl carbocations can be compared by
(a) Inductive effect
(b) Hyperconjugation
(c) Resonance.