ABC News | Video Report by David Muir, ABC News: A long way since that first computer with a hard drive in the 1960s could store about one Manhattan phone book, Watson can hold 12 million of them.

In the 1980s, IBM’s first PC could understand about 5,000 words — Watson: 125 billion.

But sometimes that data misses the human subtlety. Scientists will tell you that even though Watson can handle 80 trillion instructions per second, that the human brain is still capable of far more.