What is an extended partition and how do I create one?

Question

File systems

I wanted to install Ubuntu, but because Windows has a hidden drive with BitLocker and stuff, I can't create a second volume for /home. I read about it on the Internet, I heard about the extended section. As I understand it, this seems to be the same regular partition, only it already contains folders or how, for example, the OS and the / home partition are distributed, or am I mistaken? And how to create it by the way?

Answer 1

Read about MBR and GPT.
In the MBR, only 4 positions (16 * 4 bytes) are allocated for the partition table. It
is physically impossible to place more partitions in the MBR record.
But you can make one extended partition, inside which you can create your own partition table, and accordingly create additional subsections in the extended partition, and format them already. So you can bypass the limitation of 4 partitions on the disk.
Extended can be only one. You cannot create primary after extended.
In GPT, the partition table is stored differently. there is no such restriction, and the extended section is not needed.