Partitioning is a means to divide a single hard drive into many logical drives. A partition is a contiguous set of blocks on a drive that are treated as an independant disk. A partition table is an index that relates sections of the hard drive to partitions.
http://www.tldp.org/HOWTO/Partition/index.html The Linux partition ?HowTo.
http://staff.washington.edu/trav/linux/lost_partition.html Recovering a Lost Partition Table