This is the 67th most frequent Italian word.
invece
Instead; on the contrary.
In this case, 'invece' expresses an unexpected opposition or contrast to an anticipation.
Mi aspettavo che fosse gentile, invece si è comportato male.
I expected him to be kind; however, he behaved poorly.
Here, 'invece' highlights a difference between two subjects, drawing a comparison.
Lui studia scienze, invece sua sorella studia lettere.
He studies science, while his sister studies literature.
Here, 'invece' indicates a contrast between two ideas, showing an alternative occurrence.