The state of matter that has a definite shape and volume is a solid.

Explanation

• Solids have particles tightly packed in a fixed arrangement, which gives them both a definite shape and a definite volume. This means a solid maintains its shape regardless of the container it is in and occupies a consistent volume.

• In contrast, liquids have a definite volume but no definite shape, taking the shape of their container.
• Gases have neither a definite shape nor a definite volume, as they expand to fill their container.

Thus, the defining characteristic of solids is their definite shape and volume.