Getting confuse of so many term used in phone card or calling cards industries?
Here are some basic and common phone card glossary which might be useful. 

Connection Fee
A fee charged on every call that is made.   

Carrier
A telecommunications provider which owns switch equipment.

Interstate
Between multiple states.

ISDN (Integrated Services Digital Network)
Phone line service whose technology offers more bandwidth more economically; it is therefore better suited for Internet telephony and video applications. ISDN uses multiple channels for data and voice.

Personal Identification Number (PIN)
Personal unique security codes that callers use to access their accounts

Rechargeable Phone Cards
A calling card used which can be refilled with units by the addition of funds to the calling card account without the purchase of a new card or a new PIN.

Surcharge
An additional charge on top of a base rate for a specified reason. A fee charged against the card usually to cover the companies costs

Cards Service Fee
A fee that will be charged to your phone card credit , which can be based on weekely, monthly or per call.

Telephone cards
Same as a phone cards or calling cards.