You're likely to come across something called LVM or Logical Volume Manager. LVM is pretty complex, but in short it allows us, as administrators, to do more complex, flexible and powerful partitioning versus what we were doing above. Instead of just "physically" partitioning the disk, we use LVM to create logical partitions for us.
It can do more, however. For example, you can create "Volume Groups" (VG) and inside of those you can create "Logic Volumes" (LV). These LVs are your partitions, and the VG groups them together. This allows you to do all kinds of very cool things like mirroring, stripping across multiple disks, etc. It's a very powerful system, but I'm seeing it less and less as time goes on.
If you run Ubuntu on a desktop (perhaps the Ubuntu Desktop distribution), then you'll very likely have an LVM setup on your disk(s) or XFS, which is a more modern equivalent.
I recommend putting this topic to the side for now.