'ref'和'out'关键字之间有什么区别？

public static void RefExample(ref int value)
{
    value = 10;
}

public static void OutExample(out int value)
{
    value = 20;
}

public static void Main()
{
    int refVar = 5;
    int outVar;

    RefExample(ref refVar);
    OutExample(out outVar);

    Console.WriteLine("Ref: " + refVar); // 输出：Ref: 10
    Console.WriteLine("Out: " + outVar); // 输出：Out: 20
}