What does default(object); do in C#?

Question

Googling is only coming up with the keyword, but I stumbled across some code that says

MyVariable = default(MyObject);

and I am wondering

Answer 1

When constraints have not been applied to restrict a generic type parameter to be a reference type, then a value type, such as a struct, could also be passed. In such cases, comparing the type parameter to null would always be false, because a struct can be empty, but never null

wrong code

public void TestChanges(T inputValue)

            try
            {
                if (inputValue==null)
                    return;
                //operation on inputValue

           }
            catch
            {
                // ignore this.
            }
        }

corrected

public void TestChanges(T inputValue)

            try
            {
                if (object.Equals(inputValue, default(T)) )
                    return;
                //operation on inputValue

           }
            catch
            {
                // ignore this.
            }
        }