(a) Condensation- The process of changing a gas (or vapour) to a liquid by cooling is called condensation. When steam (or water vapour) changes into water on cooling, it is called condensation of steam.

(b) Freezing- The process of changing a liquid into a solid by cooling is called freezing. When water is cooled, it gets converted into a solid called ‘ice’. This is called freezing of water. Freezing means solidification.