indicators of the indicator

Orif Yusufjonov:

Hello everybody! 

Why are different readings of the indicator in the trade window, from the window of the tester ? The errors are not large but it affects the test results very much
. The expert Advisor traded the day spent on the same day on the tester most of the orders in the tester are not visible at all . In my opinion this tester is complete
bullshit.

1. What do errors mean? 
2. What mode
   generation of ticks is selected in the tester? 
3. Where is the code, after all?