Ventilation = the movement of fresh air around a closed space or the system that does this.

• Our kitchen has poor ventilation and in summer it becomes unbearably stuffy.
• Use car ventilation system for fresh air circulation.
• Good ventilation helps to reduce indoor pollution but this is not always possible.

Aeration = the process by which air is circulated through , mixed with or dissolved in a liquid or substance.

• Aerate the soil by digging.
• Blood is aerated in the lungs.
• Aerated water.
• Earthworms help to aerate the soil.
• Aeration is used to maintain the health and vitality of the fishes.
• Aerated drinks.
• Pond owners provide artificial aeration in their ponds.