What is the difference between the time zone format of Fedora and Ubuntu (& Debian & Arch ??

What is the difference between the time zone format of Fedora and Ubuntu (& amp; Debian & amp; Arch ?? -- Linux general technology-Linux technology and application information. for details, refer to the following section. The title may not be clear. I will describe the process of my cup in detail ..
The computer originally had three primary partitions (recovery partition, system reserved, C: \, extended partition)
The previous installation of fedora16 is: 1. in the extended partition under win7, 30 GB space is drawn by deleting the volume (changed to a Green free space) 2. install fedora, partition by flow, and then install fed3. after the installation is complete, go to win7 again. in the Disk Manager, we can see that the three partitions (/boot // home) of fedora are included in the extended partitions like the D and E disks of win7 .. After the Ora partition is deleted from the volume, the 30 GB space is still in the extended partition (Green free space)
When I installed ubuntu again, I used the same method, but in the Disk Manager of win7, I saw that the three partitions of ubuntu are no longer in the extended partitions, instead, it is independent of three primary partitions. now the disk has seven primary partitions .. I don't understand why the difference exists between fedora and ubuntu in terms of partitions, and not all disks have a maximum of four primary partitions? I am afraid to delete the three partitions of ubuntu, because the 30 GB is in the inactive status (black) and cannot be used, unless you delete the entire extended partition and create a new extended partition for all the spaces... Can someone explain the reason? Is there any remedy?