As the classic song goes “Why do fools fall in love?”. Not “How do fools fall in love?”. Why do people yawn, not How do people yawn. The three year old that’s always asking “Why, why, why” not “how, how, how”.
So “why” is this? The “why” provides deeper understanding, insight, and motivation behind the “what”.
In technical training it’s easy to show the how. “Here’s how you create a lookup table in Excel” for instance. But explaining why you want to create a lookup table can provide useful background spark the imagination of the student to apply it to their own work situation.
Training is usually part of an overall change management strategy. To help ensure adoption of that change, providing the logical reasoning behind why something works the way it does, in addition to the how, will increase the chance of training success.
This article provides more insight as to the importance.