In order of increasing intensity: Graffiti can be tags, throwies, burners or pieces.
Tags are those quick stylized signatures, a note left behind or a harbinger of bigger graffiti to come.
Throwies can also be called fill-ins—these are often two-color works, solid letters with an outline and shading, often closely resembling the tag, only larger.
Burners add more complexity, and the name evokes a simmering hipness—burners are hot, as in they’re way too cool. They can have three or four colors, and because the time it takes to write a burner is longer, the letters are usually cleaner and there is more intent in overall composition.
Finally, the term piece is short for “masterpiece,” and these are more often than not legal or commissioned works.
With graffiti, there’s a name for everything. The term for going out and writing graffiti is “bombing.” The visual of a plane strafing a city is not inappropriate here. Graffiti is the art of conflict and demolition of the pre-existing order, and writers see themselves as the soldiers in the war against the empty wall. Like our aerial bomber, writers can engage in a variety of bombing tactics—covering an entire area with tags and throwies, or selecting high-value targets for burners.
But this language of brute force fails to describe the romantic irony in my two favorite terms in graffiti. Heaven refers to spots that are so high they have such a level of difficulty that a wrong step could end in death—Heaven having a tragic double meaning, comprising both an oversized aspiration and an acknowledgement of the perils of ambition.
A term not used much anymore, but beautiful in its own way, is invention, which is basically a polite way of saying “stolen,” but really gets at the core of a graffiti ethos. You might say that you invented that spray paint, when you mean that you stole it. The larger meaning, however, is more descriptive of graffiti culture as a whole: from nothing into something, from a blank wall to art, from obscurity to fame.