The "Tecnique" is "How", not necessarily "Why". The "Tool" is "Why". With the "Why" you can develop several "How".

When you know simply and only the "How", you get stuck into the only "how".
When you know also the "Why" then you can change your recipes and also invent new ones.

You might know "how" to make a bechamel with
50 gr of butter
50 gr of flour
500 gr of milk

Do you know the "Why" of this ratio?
Do you know the "Why" of the procedure?

Do you know that you can change it? How?

There are many "Hows", but only one "Why": the knowledge that you need to have in order to become a real creative cook.

When you know "The Power of the Flour", the capability of absortion of the starch, the coagulation of proteins, the behave of sugar on the heat ( and many others) ... then you can elaborate techniques.

The "knowledge of what happens" is the "Tool" that you need in order to ... just use it, that is to develop the methods and the techniques.

Thus we can call:
the science as Why
the technique(s) as How

............As well as a carving knife is a tool.

Depending the way - or the technique - you handle them, you would have a different effect.

in this photo the Vegetable Carving Artist Steven Turnor with Chef Giovanni Stecca and me

Thus, when you know what a blade with a particular shape can do ( knowledge) , handling it in a certain way( technique), can bring you ............

...............to a desired result.

In the same way, knowing - for istance - how the sugar behaves with the heat ( knowledge = tool), you can transform it into a syrup, a crunchy caramel, a flexible doug