I use Deceased on Line.
You can see the people buried in the same grave from your initial search for an individual.
However if a grave number has been transcribed incorrectly - someone else can be shown as buried there! That happened with my grandparents grave. There was a stranger with them.
When I looked at the original register entry for that person - it gave her husband's name - so I looked for him, found him and I could see his grave number - and could also tell how my 'stranger's' grave number had been mistranscribed. I think it depends on the cemetery and possibly the period - as to the details included.
I contacted Deceased on Line about the error and they corrected it.
In my local cemetery, it usually says things like 'wife of' or 'widow of' - where they died, and if it was in hospital - sometimes their home address is given also. In addition you see the name of the person applying for the grave and of course - the grave number.
In cremation cases it will say if the ashes have been scattered.
I do think the info may vary from place to place though.