The first-person pronoun 'I' or 'me'. Slightly formal and often used by women; in general contexts it's a common polite way to refer to oneself.
私は大学で経済学を勉強しています。
I am studying economics at university.
すみません、私はその本を借りた覚えがありません。
Excuse me, I don't recall borrowing that book.
私の趣味は写真を撮ることです。
My hobby is taking photographs.
面接では『私は〜』という表現で自分の強みを話してください。
In the interview, talk about your strengths starting with 'I' (watashi wa...).