Three different ways to work through a problem. Most people prefer one but can practise the others.
Example
You are stuck on a maths question. You could draw it as a picture (visual). You could explain it out loud to a friend (verbal). You could write the steps in order (step-by-step). One of these usually clicks faster than the others.
How it fits in
Your natural route is the one you reach for without thinking. Your stretch route is a second option you can practise. Knowing both gives you somewhere to go when the natural route stalls. Strong learners usually have one route they trust and one they keep building, not three equally good options.
Where this is taught
Related terms
The way of thinking you reach for first, plus a second one you can practise for when the first one stalls.
Explain a topic out loud as if teaching a ten-year-old. The places you stumble are what you do not yet understand.
Test yourself instead of re-reading. Pulling information out of your head is what builds memory, not putting it back in.