What does that mean in plain English?

你能不能用大白話解釋一下？

Saying and doing are two things.

說與做是兩回事。

when they would be capable of providing information about traffic jams and suggesting alternative routes, when they would be used in hospitals to help doctors to diagnose illnesses, when they would relieve office workers and accountants of dull, repetitiv

計算機可以使辦公室人員和會計免除那些枯燥、重復的勞動。