Unlike photoperiod strains, autoflowering strains start to mature and make flowers/buds on their own without any change in light schedule. This keeps plants small and acting more like houseplants. Autoflowering strains are essentially immune to problems from light leaks (light at the wrong time can cause accidental re-vegging or hermies in photoperiod plants). Autoflowers are also known as cannabis ruderalis. Most modern autoflower strains are a blend of ruderalis and photoperiod indica/sativas.