Final answer:
The MBR uses 64 bytes for partition entries, with each of the four entries taking up 16 bytes. Each entry describes a single partition, and although the MBR is limited to four primary partitions, one can be an extended partition for more subdivisions.
Step-by-step explanation:
In the context of Master Boot Record (MBR), partition entries are an essential component. The MBR is the first sector of a storage device and contains the information necessary to boot the system along with partition information. MBR allocates 64 bytes for the partition table, which houses the partition entries. Each entry is 16 bytes long, so there are four partition entries available in the MBR scheme (64 bytes divided by 16 bytes per entry).
Each of these 16-byte entries describes a single partition, indicating attributes such as the starting and ending sectors, the size of the partition, and whether it is bootable. Due to this structure, the MBR is limited to four primary partitions. However, one of these primary partitions can be an extended partition, which can then be subdivided into more logical partitions.