Your "responsibilities" at work are things that you're supposed to do. You can talk about your responsibilities in general:

I'm responsibile for all of the company's hiring decisions.

But you can also talk about "day-to-day" responsibilities. These are small tasks that you do each day:

Your day-to-day responsibilities will include things like answering customer emails, scheduling travel arrangements for the sales team, preparing for team meetings, and things like that.