What state of matter is often described as having a definite shape and volume?

The state of matter that is characterized by having a definite shape and volume is solid. Solids have closely packed particles that vibrate in place, which gives them a fixed structure. This arrangement of particles allows solids to maintain their shape and volume under normal conditions.

In contrast, liquids have a definite volume but take the shape of their container, while gases have neither a definite shape nor a definite volume, expanding to fill the entire space available. Bose-Einstein condensates represent a state of matter that occurs at extremely low temperatures where particles behave collectively in a unique quantum state, but they do not fit the description of having a definite shape and volume in the same way that solids do. Therefore, the characteristics of solids align perfectly with the definitions provided in the question, making it the correct answer.