My understanding is that the container is a partition:
A partition formatted as an APFS container. Splitting hairs, I agree!!!
But sometimes(?) it can help to aware of the partition table which only contains details of the partition locations (on the physical disk) and their types.
The sudo gpt -r show disk0 displays the partition table, but on a running system does not work for the boot disk. Here is the output for an external disk (disk6) with a bootable system (disk8) and another APFS formatted partition (disk7):
sudo gpt -r show disk6
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 156250000 2 GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
156659640 820113488 3 GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
976773128 7
976773135 32 Sec GPT table
976773167 1 Sec GPT header
Those UUIDs are "well known" types - in this case EFI and APFS.
diskutil list disk6
/dev/disk6 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.1 GB disk6
1: EFI EFI 209.7 MB disk6s1
2: Apple_APFS Container disk8 80.0 GB disk6s2
3: Apple_APFS Container disk7 419.9 GB disk6s3