Who are Hannas rivals in Pretty Little Liars?

In "Pretty Little Liars," Hanna Marin's main rivals include Mona Vanderwaal, who initially appears to be her best friend but later becomes one of the show's antagonists. Additionally, the character of Alison DiLaurentis often poses a challenge for Hanna, as their complicated history and Alison's manipulative nature create tension. Throughout the series, Hanna also faces rivalry from other characters involved in the overarching mystery and conflict, including the elusive "A."