According to X means “in X’s opinion”, “if what X says is true”.

According to Harry, it’s a good film.

The train gets in at 8,27, according to the timetable.

We do not usually give our opinions with according to. Compare:

According to Ann, her boyfriend is brilliant.

(= If what Ann says is true, …)

In my opinion, Ann’s boyfriend is an idiot. (NOT According to me,...)

(Taken from Michael Swan, Practical English Usage, Oxford)