stderr redirection to stdout

Question

To redirect stderr to stdout we use 2 > &1. Why is it not just 2 > 1? why & is needed?

Answer 1

because your stream would be redirected to file named "1"

Answer 2

Because 2>1 would redirect to a file named "1". The & symbol specifies a stream rather than a file. The & symbol is not necessary for the 2 because the 2 is always a stream inidcator