Final answer:
Pie-shaped wedges on a hard drive are sectors, which are parts of the tracks where data is stored magnetically.
Step-by-step explanation:
The pie-shaped wedges on the surface of a hard drive are sectors that are part of the concentric circles called tracks. A hard drive stores data magnetically on a rotating platter. Each track is divided into the segments called sectors. These sectors resemble the pieces of a pie and are the smallest units that can be read from or written to. The hard drive's read/write head moves across these tracks and sectors to access or store information.