What did Bateson mean when he wrote “information” is “a difference that makes a difference”?

Bateson on Information

What did Bateson mean when he wrote
“information” is “a difference that makes a difference”?

The original title of this document was:
Bateson did not define “information” as
“a difference that makes a difference”
(And he would have been rather silly if he had.)Aaron Sloman
http://www.cs.bham.ac.uk/~axs
School of Computer Science, The University of Birmingham, UK