Prices in MqlRates - bid or ask price?

 
struct MqlRates
  {
   datetime time;         // opening bar time
   double   open;         // opening price Open
   double   high;         // the highest price High
   double   low;          // the lowest price Low
   double   close;        // the closing price Close
   long     tick_volume;  // the tick volume
   int      spread;       // spread
   long     real_volume;  // market volume
  };  

 Are high and low in MqlRates function Ask price or Bid price? 

 
jaycode:

 Are high and low in MqlRates function Ask price or Bid price? 

Bid price. All charts in historical data are based on bid price.
 
angevoyageur:
Bid price. All charts in historical data are based on bid price.
Thank you for answering, I really appreciate that!
 
I also think that All charts in historical data are based on bid price
 
therefore should you use bid price to do your analysis?
Reason: