What makes modern linguistics different from traditional grammar?

What makes modern linguistics different from traditional grammar?

Traditional grammar is prescriptive（规定性）; it is based on "high "(religious, literary) written language. It sets models for language users to follow. But Modern linguistics is descriptive（描述性）; its investigations are based on authentic and mainly spoken language data. It is supposed to be scientific and objective and the task of linguists is supposed to describe the language people actually use, whether it is "correct" or not.