c# - what is the meaning of data hiding -

one of important aspects of oop data hiding. can explain using simple piece of code data hiding , why need it?

i'm guessing data hiding mean encapsulation or having variable within object , exposing , modify methods, when want enforce logic setting value?

public class customer {     private decimal _accountbalance;      public decimal getbalance()     {         return _accountbalance;     }      public void addcharge(decimal charge)     {         _accountbalance += charge;         if (_accountbalance < 0)         {             throw new argumentexception(                 "the charge cannot put customer in credit");         }     }     } 

i.e. in example, i'm allowing consuming class balance of customer, i'm not allowing them set directly. i've exposed method allows me modify _accountbalance within class instance adding via charge in addcharge method.

here's article may find useful.