And now the depth of my ignorance has resurfaced. What is the reason for this valve and is it better or worse than the conventional Schrader valve?
I have two adaptors and my emergency on board hand pump has a smaller side to the inflator head so that is now explained. I also have a new "trim" position on the front derailleur control that I am still trying to figure out. I understand it and it has been completely explained to me at the store but when on the road I am still working out the mechanics. The Quick 3 is a lot more bike than I have ever had and I obviously have a lot to understand. Makes me wonder how lost I would be if I had bought a high end road bike.
Frank.

Presta valves are narrower than schrader, and thus are less intrusive on the rim's strength.

It's just another standard. The main advantage of schrader valves is that the valve is less delicate and is better-protected by the stem. But for the most part, for bicycles, I prefer presta:
-They're lighter.
-The narrower stem makes them less intrusive on rim design.
-They take up less space in something like a saddle bag.
-You can let air out without tools.

I don't think it really matters much either way. As long as you know how to use either, they both work. Higher-end bicycle stuff generally comes with presta, though.

Probably no more lost than you are now. A road bike being high-end doesn't necessarily mean that it's a complex machine.

Regarding the valves, both do work. I find that Presta valves come on both high- and low-end bikes. My daughter's $299 Raleigh Alysa has Presta valves and the GT Aggressor Pro that I bought for her at Dick's Sporting Goods (also $299 on sale) has Presta valves. I usually drill out my Presta rims to fit Schrader valves, and standardize on that design. The thing I like most about Presta is the external threads and the lock nut. These are available in Schrader, though can be harder to find. Specialized makes tubes with fully threaded Schrader valves, and I get these at my local Specialized dealer. Presta definitely have an advantage with narrow rims -- it's easier to cram both beads and the valve between the rim lips if the valve is narrow. I tend to ride wider wheels, though, where this is not a concern.

Thanks all. Frank.

personally, I drill them out & use a schrader valve tube. the difference in diameter is insignificant

Presta has no internal check valve spring, like Schrader valve cores do , they have a check valve ,

but it is closed by the air pressure difference being higher in side than the surrounding atmosphere..

with a hand pump you only make the air in the pump higher than whats in the tube
without a spring keeping the valve closed, to work against,..

Thank you all for the information.
Frank.