Well I was just wondering what partition belongs to which. On my computer I have Windows 7 and two Ubuntu systems (it was an accident, which is why I need to know which partition is which). So how do I know which one is which??

PS here's the codes:

jp@jp-Satellite-L555D:~$ sudo update-grub
[sudo] password for jp: 
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.11.0-12-generic
Found initrd image: /boot/initrd.img-3.11.0-12-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
Found Windows 7 (loader) on /dev/sda2
Found Windows Recovery Environment (loader) on /dev/sda3
Found Ubuntu 13.10 (13.10) on /dev/sda7
done

jp@jp-Satellite-L555D:~$ sudo fdisk -l

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf6f5148e

Device Boot         Start         End      Blocks   Id  System
/dev/sda1   *        2048     3074047     1536000   27  Hidden NTFS WinRE
/dev/sda2         3074048   213421022   105173487+   7  HPFS/NTFS/exFAT
/dev/sda3       469676032   488396799     9360384   17  Hidden HPFS/NTFS
/dev/sda4       213422078   469676031   128126977    5  Extended
/dev/sda5       300185600   463910911    81862656   83  Linux
/dev/sda6       463912960   469676031     2881536   82  Linux swap / Solaris
/dev/sda7       213422080   300185599    43381760   83  Linux

Partition table entries are not in disk order

Thanks to whoever can answer this. Another quick question, what is the extended partition??