Electronic Money Closely Tied up with Fiat Currencies
 ↑
│ Smart Cards or Mobile Phones
│     (e.g., Credit Cards, Debit Cards, Prepaid Cards)
│ PayPal, Apply Pay, Android Pay
│ Mileages or Reward Points of Loyalty Programs
│ Cryptocurrency
│ Currency in a Virtual World
 ↓
Electronic Money Independent from Fiat Currencies
(Practically impossible to be completely independent)