cRank is a natural number, representing the relative position of the user across The XENB ecosystem. For example, a cRank of 2,420 represents the fact that 2,419 users before you have decided to mint XENB for themselves and have submitted their claimRank transactions before you did.
XENB smart contract also tracks a Global cRank within the ecosystem and increases every time someone else joins as a participant and generates their cRank.