Siard composed on 2022-06-09 16:03 (UTC+0200):
A disk drive can contain a maximum of four primary partitions or three primary partitions and a single extended partition.
Every one of the four entries in the portion of "the partition table" contained in the MBR represent a definition of one primary partition. Therefore, all entries in the MBR are primaries, including the extended. The extended simply serves a different purpose - extending the partition table to include sector(s) elsewhere on disk that define either additional table sector(s) that extend "the table", and/or additional partition(s). -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata