C# Equals and ==

Value type Equals and == are equivalent;
For string, after overriding, Equals and == are equivalent;
For object type, the specificity of string;
For other class types.

            object t = "123";
            object a = t;
            object b = "123";
            Console.WriteLine(a == b);
            Console.ReadKey();

            object t = 1;
            object a = t;
            object b = 1;
            Console.WriteLine(a == b);
            Console.ReadKey();

            object t = 1;
            object a = t;
            object b = 1;
            Console.WriteLine(a.Equals(b));
            Console.ReadKey();

Equals is used to compare whether the same object, but the question arises, it has two meanings:
Is it the same type, or does it mean the values are equal?

    public class Test
    {
        public int A { get; set; }
        public int B { get; set; }
    }
    class Program
    {
        static void Main()
        {
            Test a = new Test { A = 1, B = 2 };
            Test b = new Test { A = 2, B = 1 };
            Console.WriteLine(a.Equals(b));
            Console.ReadKey();
        }
    }

Result: False

    public class Test
    {
        public int A { get; set; }
        public int B { get; set; }
    }
    class Program
    {
        static void Main()
        {
            Test a = new Test { A = 1, B = 2 };
            Test b = new Test { A = 1, B = 2 };
            Console.WriteLine(a.Equals(b));
            Console.ReadKey();
        }
    }

Equals will throw an exception on null reference, while == will not.
The difference between Equals and == lies in null.