A file system has to be created for every individual partition after the partitioning process is finished (the partition has to be formatted).
Individual file systems can already be partitioned with this program. This is the easiest way because it prevents confusing one or several partitions with other partitions.
Before you utilize a(nother) program for formatting you should always verify once more that you have selected the right partition to be formatted!
If possible, you should first format all partitions before installing the operating systems. This prevents accidentally deleting an already installed operating system.
Most of the setup programs are also able to format partitions. However, these pose the risk to accidentally select the incorrect partition and thus delete an existing file system (operating system)!