Work-life interface has to do with how you balance your job (work) and your life outside of your job (family, hobbies, recreation). It's important to find the right mix of activities, so that you stay happy and productive. The way to do this is to plan and manage your time so that you don't spend too much time doing work stuff or too much time doing life stuff. Doing this will help you enjoy both your work and your life, and stay organized, productive, and relaxed.