--> this is example of boolean variable which will return either true or false.
No, that is an example of two int (I'm assuming) values being compared. Comparing boolean variables using > doesn't make sense.
--> This is non boolean variable..
The statement itself does not provide enough information to answer the question. What is the type of variable? That is what determines how to write the statement. It doesn't make sense to compare a boolean variable (containing true or false) to HIGH or LOW. So, it appears that the statement does not involve a boolean variable.