Full Idea
With ordinary finite numbers ordinals and cardinals are in effect the same, but beyond infinity it is possible for two sets to have the same cardinality but different ordinals.
Gist of Idea
Beyond infinity cardinals and ordinals can come apart
Source
Brian Clegg (Infinity: Quest to Think the Unthinkable [2003], Ch.13)
Book Reference
Clegg,Brian: 'Infinity' [Robinson 2003], p.169