Red chillies, or Laal Mirch, are dried, ripe fruits of the Capsicum plant. They are long, slender, and have a deep red color. Red chillies are known for their intense heat and pungent flavor, which can vary from mildly spicy to extremely hot. They are used in various forms, including whole, crushed, or powdered, to add heat and enhance the flavor of a wide range of dishes, from curries and sauces to marinades and pickles.