It has many facets but is best known for pepper and tobacco characteristics.
Cabernet Franc is the parent of Cabernet Sauvignon (with Sauvignon Blanc) and also a parent of Merlot.
Cabernet Franc is often looked down on in favour of Cabernet Sauvignon, but this is an unfair asessment, based purely on availability. Cabernet Franc can be less generous than "CabSav" and so is less planted, and so people rarely get to taste it solo.
It really is worth seeking out solo.