If you're talking about Cisco tech... there's the WIC - data only, VIC - voice only, and VWIC - voice and data cards. Each depends on the router as to what functions are supported/supportable based on the IOS software and the slot in which the card is loaded.
For example, a 1750 (or 1751) has 2 WIC and 1 VIC slots. The VIC slot is keyed so a WIC won't seat in it -- and if you force it in there anyway, it won't work. A VIC will physically fit in a WIC slot, but will not function there. A VWIC can go in either slot, and will function based on the type of slot -- data only in a WIC slot, voice only in a VIC slot.
A 1760 has 2 VIC/WIC slots and 2 VIC slots. A VWIC in the first two slots can be configured for either voice or data operation.