What form of English is slang?

Slang is not a form of English in the same way that British English or American English are. It's more accurate to describe it as a variety of language that:

* Uses informal words and phrases: These are often specific to certain groups of people, regions, or time periods.

* Evolves rapidly: New slang terms appear frequently, and old ones can quickly fall out of use.

* Can be used across different forms of English: You can find slang in British English, American English, Australian English, etc.

Think of slang as a layer on top of standard English, adding color and informality to communication. It's not a distinct dialect like Cockney or Appalachian English, but rather a set of words and expressions that can be incorporated into any dialect.