PPM (Parts Per Million)

The acronym PPM stands for "Parts Per Million". In the context of the Lightning Network, it quantifies the number of Satoshis per 1 Million Sats.

For example:

   1ppm is 1 sat per 1 Million Satoshis
   1000ppm is 1000 sats per 1 Million Satoshis
   4000ppm is 4000 sats per 1 Million Satoshis
   4000ppm is 1000 sats per 250k Satoshis

PPM is commonly used to express routing fees in the Lightning Network. When setting up a Lightning node, you can specify your routing fees in PPM, which determines how much you charge for forwarding payments through your node.