Venetian descends partly from Vulgar Latin - like all other Romance languages, including Italian and the other Italian dialects. However, in the traditional classification of Romance languages it is considered part of the Italo-Romance group.
According to Ethnologue, Venetian and Italian belong to different sub-branches of the Italo-Western branch: Venetian is a member of the Gallo-Iberian group, which also includes Catalan, Spanish, Portuguese and French, among others; whereas Italian is a member of the Italo-Dalmatian group. More precisely, Venetian belongs to the Gallo-Romance sub-branch of Gallo-Iberian, which includes French but not Spanish, Catalan and Portuguese. In that classification, therefore, Venetian is more closely related to French, Catalan and Spanish than to Italian.
Venetian proper can be distinguished from Venetian Italian, the variety of Italian influenced by local Venetian features that is also spoken in the region. Compare:
Venetian: Marco xe drio rivar ('Marco is arriving')
Venetian Italian: Marco (el) sta rivando
Standard Italian: Marco sta arrivando