Full Idea
The theory of infinity has two forms, cardinal and ordinal, of which the former springs from the logical theory of numbers; the theory of continuity is purely ordinal.
Gist of Idea
There are cardinal and ordinal theories of infinity (while continuity is entirely ordinal)
Source
Bertrand Russell (The Principles of Mathematics [1903], §249)
Book Reference
Russell,Bertrand: 'Principles of Mathematics' [Routledge 1992], p.259