An example, as given below, is the best way to explain this:

When the types used for Equals are different, the Equals method returns false regardless of the values:

int i = 0;
uint ui = 0;

if (i == ui)
{
  Console.WriteLine("i == ui: true");
} 
else
{
  Console.WriteLine("i == ui: false");
} 
if (i.Equals(ui))
{
  Console.WriteLine("i.Equals(ui): true");
}
else
{
  Console.WriteLine("i.Equals(ui): false");
}

This code ends with the following output:

i == ui: true
i.Equals(ui): false