Tofu is bean curd made from soy milk. There's an array of tofu options available in supermarkets these days. In general, you'll find it three ways: firm, soft, and dried. Firm tofu, pressed into shape, holds its shape and can be eaten with chopsticks. Soft tofu is prized for its creamy texture and most often eaten with a spoon. Dried tofu has a cheesy, musky flavor. "Silken" tofu is less spongy, smoother, not grainy at all. It can be found in firm or extra-firm packages. Most tofu is packaged in water to keep it fresh. It's best to remove some of that water from the medium to extra-firm varieties before sauteing or stir-frying.
Try this Kitchen Shortcut with Mao Pao Tofu.