There are no advantages or disadvantages in these partitions, it is just dat each of d 2 partition r ment 2 do different things
Partition are basically of two type
Primary Partition
Extended Partitions
The extended partition can have any number of logical drives
Only primary partitition can be made active, which means that those partitions are made bootable once OS is installed in them, whereas Logical drives made in the extended partition cannot b made bootable, only for data storage purposes
so your partitionedHDD should look sumthin like this
1 Active Primary Partition
Remaining space - Extended partition with any number of logical drives in it