Transitivity or intransitivity is a property that specifically applies to verbs. Every verb is either transitive or intransitive, though there are some verbs that can switch between the two types. Transitivity and intransitivity refer to whether a verb has a direct object or not.
Intransitive verb
no direct object:
El perro ladró.The dog barked.
Transitive verb
direct object = un bolso:
Julia compró un bolso.Julia bought a handbag.