Generally speaking, smash-and-grab burglaries are exactly the way they sound: criminals break glass displays and store windows, steal all of the merchandise they can carry, and get away before any authorities can be summoned. These crimes can be executed in less than a minute and, if product is identified properly, can be highly lucrative.
Smash-and-grabs tend to be preceded by a store casing where one of the burglars or an accomplice will repeatedly visit the store to pinpoint everything from the fastest ways in and out, to the location of security cameras, to staff weaknesses during shift changes, to, most importantly, the location of the most valuable and portable product.
Other types of smash-and-grab operations are "grab and run" crimes which involve no breaking down of showcases or windows, and instead has a thief grabbing a freestanding display and running off with it. "Crash and grab" operations are when a criminal drives a (typically stolen) vehicle through the front door or wall of a building in order to steal items before making their getaway. Crash and grab jobs, also known as "ram raids," tend to target convenience stores and are usually deployed to heist ATMs.