I want to be sure if Metatrader uses Ctrade class for sending buy and sell requests.
Does anyone know it?
I mean, when for example someone right clicks on a symbol in the marketwatch and selects "new order" and fills that form, does Metatrader use Ctrade class for sending that buy/sell/.... request to server?
You could search a little more on the forum and on the "Docs" section of this webpage !!! Maybe it would be interesting for you to download the whole MQL5 manual, available in several languages... English, Russian, German, Spanish, French, Chinese, Italian, Portuguese and Turkish.
Regarding your question, there are built in functions for sending orders in MT5... take a look at MqlTradeRequest and OrderSend. However, I strongly recommend you to donwload and read the manual.
I hope it helps.