TiVo Premiere Manual page 7

Dual tuner. A tuner is a device found inside DVRs, TVs, and
cable boxes — anything designed to receive TV signals,
including the TiVo Premiere. A tuner picks one channel to
display; it "tunes" to that channel. Your TiVo Premiere is a
"dual tuner" device, meaning that it has two tuners inside and
can record two shows at once. Pressing the Live TV button
while watching live TV will swap between your two tuners.
Decoder. A CableCARD decoder allows your
TM
CableCARD
TiVo Premiere to receive digital cable channels without a cable
box. If you subscribe to digital cable, you must request one
Multi-Stream CableCARD (M-CARD) from your cable
company. One M-CARD will let you watch and record two
shows at once.
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