Am I right that a Drive can have up to 4. Primary Partitions?

Or is it that a Drive can have 1. Primary Partitions and 3. Lagicale Partitions?http://www.pcguide.com/ref/hdd/file/structPartitions-c.htmlI did go there but one THING I don't understnd is the Partition with the OS on it is the Primary Partition.

So how can they say a drive can have up to 4. Primary Partitions on it?

If you have win xp on one Partition then this is the Primary Partition. And if the other 3. PARTITINS are just Blank they are Lgical Partitions right??This is what I ment to say.

A Drive can have up to 4. Primary Partitions and any one of these Primary Partitions can be Booted from at a time.

Now only one of the 4. Primary Partitions can be Partitioned again and this ne Partition will be called a Lagicle Drive.
And you can not Boot from a Lagicle Drive I GET all of this so far.

One thing If I make 2. Primary Partitions they booth will SHOW up a Drive Latters.
And if I Partition a Primary Partition again the new Partition that they call Lagicle Drive will also show up as a Drive.

So if all 4. Primary Partitions will show up a Drives and even other Partitions will show up as Drives as well are they all not called Lagicle Drives?

Because all I read SAYS Primary Partitions are not called Lagicle Drives why?