2000 Objects actually define multiple interfaces depending on their complexity. But this should not be hard to understand.
Most objects can do many different things.
Consider the human being in terms of a programming object. Humans are very flexible in terms of their capabilities. They can, amongst other things, move as well as sense their surroundings. Within the first category, the object may have methods such as walk, run and crawl. Within the second category, senses, we may choose to include such things as hearing, seeing, tasting and touching.