Palm sugar is produced by tapping the sap from the inflorescence of the tree and boiling it down to produce a syrup, which is then sold as is, or allowed to crystallize into various shapes and sizes.
In some instances the tree itself is tapped rather than the flowering spikes, but this is an isolated production method.
Often the distinction is made between coconut sugar and palm sugar, but this only reflects the different species from which the sugar is sourced, i.e. coconut sugar is produced in an identical way.
Thailand is one place where the distinction is made and the difference is due to palm sugar being produced there from the tree trunk of the sugar palm, whilst coconut sugar is tapped from the inflorescences of the coconut palm.
The differences are semantic, as all the sugars under their various names are still produced from the sucrose-rich sap of a palm species.