Start by explaining that sensory memory is the first out of three levels of memory: sensory, short-term and long-term memory.
Explain that sensory memory retains a fleeting impression of a sensory stimulus, even after the stimulus is over. For example, if you see a car drive by the car may still be vivid in your memory for a brief time after the car has disappeared from view. Or, if you touch a vegetable, such as a tomato, you may have sensory memory of the feeling shortly after you have stopped touching it.
Explain that sensory memory applies to all the senses: vision, hearing, smell, taste and touch.
Explain that for putting sensory memory to any real use, you will need to focus on an object, feeling, sound or taste until you can discern actual details. This is the best chance to pass sensory memory on to short-term memory.