How are logical partitions represented in Linux?

Question

In the texts I study (like: LPIC_1 study guide by R.W. Smith), the linux partitions have been introduced directories split as /home, /boot, /usr and /etc...

Looking at what lsblk returns as follows:

    NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
    sda               8:0    0 465.8G  0 disk 
    ├─sda1            8:1    0   100M  0 part 
    ├─sda2            8:2    0 195.2G  0 part 
    ├─sda3            8:3    0 146.5G  0 part /run/media/user/28082EC8082E953A
    ├─sda4            8:4    0     1K  0 part 
    ├─sda5            8:5    0   500M  0 part /boot
    └─sda6            8:6    0 123.5G  0 part 
      ├─fedora-swap 253:0    0   7.9G  0 lvm  [SWAP]
...

We can see SCSI drivers and their partitioning tree and their mount points (which were introduced as common partitions in linux as mentioned above.)

I'm kind of confused by the concept of partitioning in linux. Do we call the logical partitions of the physical disks (sda, sdb) partitioning or the directories such as /home or /boot or...?

If logical partitions of physical disks (sda1, sdb1 and ...) are the partitions, what do files like /dev/sda2 represent?

Answer 1

The logical partitions (like sda1, sda2) of the physical disks (like sda, sdb) are the partitions.
So partitioning is the task of modifying the partition tables of these physical disks.
The Folders are only mount points where you can mount the partitions.

I guess because the most partitions have a specific mount point (like /home) its obvious to name the partions after there mountpoint. Like /dev/sda1 is mounted to /home so thats now our home partition or /home partition.

The /dev directory contains among other things the software representaion of the hardware devices: en.wikipedia.org/wiki/Device_file#Block_devices
sda1 is the partition but the the coresponding software interface is /dev/sda1 ... And because its a direct representation you can call /dev/sda1 a partiton too.