If you eat only one way in Venice, make it this one: standing at a bacaro (a small, old-style wine bar), working through a plate of cicchetti with a small glass of wine.
What cicchetti actually are
Small bar snacks, usually displayed along the counter: crostini topped with baccalà mantecato (whipped salt cod), marinated vegetables, tiny meatballs (polpette), sarde in saor (sweet-and-sour sardines), or a simple slice of bread and cheese. You point, you're served, you eat standing at the bar or a nearby ledge — it's closer to Spanish tapas culture than a sit-down Italian meal, and it's genuinely how a lot of Venetians eat lunch or an early dinner.
The ombra
Order a small glass of house wine — an ombra — alongside your cicchetti. The name (literally "shade") supposedly comes from vendors who used to move their wine stall to stay in the shadow of the Campanile as the sun moved across the square.
How to do a proper giro d'ombre
A giro d'ombre ("round of shadows") is the classic Venetian bar crawl: two or three cicchetti and one ombra at each stop, then moving to the next bacaro a few streets over, rather than sitting through a long single meal. Cannaregio's Fondamenta della Misericordia and the streets around the Rialto market are the two best-established areas for this.
Practical notes
Cicchetti bars are typically busiest around midday and again from early evening (roughly 6–8pm) — later than that and some kitchens start winding down. Standing at the bar is standard practice and noticeably cheaper than any seated table nearby, so don't feel you need to be offered a seat.