how does `block device`, `filesystem`, and `mount` work together

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when we wanna use a new storage hardware on the linux system, we need to
- physically connect the device
- partition the device if needed
- put a filesystem on it (laymen term: reformat)
- mount the device to a location on the linux’s directory tree

in action:

lsblk to see what devices are connected physically
fdisk /dev/sdb to partition /dev/sdb
- /dev/sdb becomes /dev/sdb1, /dev/sdb2, etc
sudo mkfs.ext4 /dev/sdb1: create filesystem ext4 on block device /dev/sdb1
mkdir -p /home/mydata: create a location for the block device to mount on
sudo mount /dev/sdb1 /home/mydata: mount the block device to the location /home/mydata
df -h to verify