Impendance - Resistance & the story of "Z"

Can someone please help a non-engineer understand the difference between the two with regard to cable deisgn. (Aren't they the same? Is it me or is the use of both terms somewhat confusing?)

Reading a certain manufactures literature, it states that lower "Z" in a cable is always better. Is this really true and can someone explain why? They have an interesting graph showing their cable with a "Z" below 1.0 and all other cables tested with "Z" above 1.0

Just looking to understand. Thanks.