What does "on the rocks" mean in bar terminology?

"On the rocks" in bar terminology refers to a drink that is served over ice. This method of serving is popular for many types of cocktails and spirits, as the ice not only chills the drink but can also slightly dilute it as it melts, which may help to balance flavors. When a drink is requested "on the rocks," the bartender typically fills a glass with ice and then pours the drink directly over the top. This technique is preferred by many patrons who enjoy their beverages cold and with a slower dilution to savor the taste over time.

The other options do not reflect common bar practice; for instance, serving a drink warm is generally undesirable for most spirits and cocktails. Shaking a drink typically refers to mixing it with ice to chill and dilute it rather than just serving it over ice. Finally, while some drinks may indeed be served in a tall glass, this is not a specification for "on the rocks" and is more about the glassware used rather than the method of serving the drink itself.