When was The Beatles first second and third style period and what was it called?

The Beatles' first style period, known as the "Mop Top" era, spanned from 1960 to 1964, characterized by their early pop sound and catchy melodies. Their second style period, often referred to as the "Psychedelic" era, lasted from 1965 to 1967, marked by experimental music and innovative studio techniques. The third period, known as the "Late" or "Post-Psychedelic" era, occurred from 1968 to 1970, showcasing a more diverse and mature sound with complex themes and arrangements.