I am downloading Forex historical data on USD/CHF (1Minute chart) from DukosCopy, which contains columns Open, High, Low, Close, Volume

[![enter image description here][1]][1]

I've just recently learnt how the price works - through the Depth of Market - a.k.a. 'Level 2 data', where agressive buying fulfills many sell limit orders. Similarly, agressive selling fulfills fulfills many buy limit orders. As I understand, these are what move the price.

What's strange for me, is this entire file is for the Ask data only. It's also possible to download a similar file for Bid data only.
 

**Question:**

**1)** Looking at the above image for the Ask (prices that a seller is willing to receive),  Why High is so close to Low?  If I interpret it correctly, High means "the highest possible **sell** limit order witnessed at that time". I would assume at least 1 person having a limit order sitting at some ridiculous place, like '5.1234'.  The volume of 96199996.9 LOTs surely will have someone like that - thus, High should be far above Low?

**2)** Or is it the highest limit order that *was fulfilled*, not merely awaiting? (Thus it's somethng similar to 'Time And Sales' of MetaTrader 5, aka Level 1 data)

**3)** A total-beginner question - are these values already including the commission of a broker that provided such a historical data? (is it already embedded in these numbers? Is it a simple offset of O H L C?) 

**-Edit:** I now think that Open, High, Low Close are prices which had the best-available limit order (non-fulfilled yet).  However, in that case, why don't we then have the OpenVolume,  HighVolume,  LowVolume,  CloseVolume.  What does the "Volume" mean in our case and why does it suffice?

**4)** Would the Volume be more useful had I selected 'Ticks'  instead of '1 Minute' data?

  [1]: https://i.sstatic.net/tQamg.png