The partition table in OS, that contains the information about all your logical disks or partitions, resides in the 0 sector of your hard disk. Your device is listed in the partitions table as /dev/sda, /dev/sdb and so on. The sd* device refers to SCSI or SATA disks on your system.
The command to see the list of partition table are :
$ sudo fdisk -l
This is what the various column indicate:
Device-Name of the device/logical partition
Boot-The * sign in this column indicated that the respective partition contains the bootloader information that is used to boot your system
Start-The starting sector allotted to this partition.
End-The ending sector allotted to this partition.
Sectors-The number of sectors allocated for this partitions.
Size-The size of the partition.
ID-An ID used by the system for this partitions
Type-The file type or system used by this partition.