A portfolio is simply the proof of a year's learning, gathered in one place — writing samples, a reading list, photos of projects, a log of what was covered. In states that ask for one, a reviewer glances through it once a year; in states that don't, families keep one anyway because it's the easiest answer to 'are we doing enough?' The trick is capturing the work as you go rather than scrambling in spring. About Time's portfolio tools assemble yours from the entries you've already logged.