The baroque era in music lasted roughly from 1600 till 1750, which is usually subdivided into early baroque (1600-1650), high baroque (1650-1700) and late baroque (1700-1750).
The classical era in music, the transition from baroque to romantic music, lasted from around 1750 till 1800. In this period the symphony as a seperate work of art was developed. Another characteristic is the so-called sonata form, a way to structure music. The term classical for this music refers to the ancient Roman and Greek cultures, that were idealised in that era.