The term "solid phase" refers to a state of matter where particles are closely packed together, resulting in a definite shape and volume. In this phase, atoms or molecules vibrate in fixed positions but do not move freely, which gives solids their rigidity. Common examples of solid phase materials include metals, ice, and wood. In contrast to the liquid and gas phases, solids have a higher density and are less compressible. The arrangement of particles in the solid phase can be crystalline, like in salt or diamond, or amorphous, like in glass. This structure influences the material's properties, such as strength and thermal conductivity.