When a substance is close to absolute zero, it is usually in the solid state. At the lowest temperature, which is roughly -273.15°C or 0 Kelvin, where a substance’s thermal energy is negligible, is absolute zero. Particles lose the majority of their energy and mobility at such low temperatures, which confines them to fixed locations inside the highly organized structure that characterizes a solid.
At greater temperatures, particles have enough kinetic energy to move freely, forming liquids, gasses, or plasmas. However, approaching absolute zero, this energy is so low that free motion is unsustainable. For example: