What is the best way to compare workflow current date and a datetime column in a list?

Hi @Messam 

You can use either the Run-If or the Conditional Branch action to compare Datetimes.

You can compare with the Greater Than (>) or the Lesser Than (<) operator.

Comparing for Equality (==) requires a little more effort. Equality comparison will always fail. While the date are the same, the time are different. Convert the Datetimes value into a Short Date or Long Date String. Use a Build String action on a DateTime variable.
Once converted into String type, you should be able to compare for Equality.

Hope that helps