A blender is ideal for smoothies, drinks, soups, and sauces because its jar and blade system are optimized for liquid movement. A mixer grinder usually includes smaller jars and a stronger grinding setup for dry spices, chutneys, batters, and thicker mixtures.
Choose based on the foods you prepare most often, motor wattage, jar sizes, blade quality, overload protection, and service support. Many kitchens benefit from both functions, but a multipurpose mixer grinder may be the more versatile first purchase.