What is the difference between Call By Value and Call By Reference in C#?

In C#, the difference between Call By Value and Call By Reference lies in how arguments are passed to methods: Call By Value: A copy of the variable's value is passed to the method. Changes made to the parameter inside the method do not affect the original variable outside the method. Call By Reference: The reference (address) of the variable is passed to the method using the ref or out keywords. This allows the method to modify the original variable directly, as it operates on the reference rather than a copy.