A Partition, put simply, is a segment of a Hard Drive that is self-contained, and seperate from other portions of the drive.
Let's take an 80GB Hard Drive as an example. Usually, a Drive like this will actually have a Formatted Capacity of around 74GB
So, a Partition Table might look like this:
| Partition Number | File System | Partition Size |
| Partition 1 | FAT32 | 8GB |
| Partition 2 | NTFS | 20GB |
| Partition 3 | Ext3 | 20GB |
| Partition 4 | Ext2 | 20GB |
| Partition 5 | FAT32 | 20GB |