Please follow https://pubchemblog.ncbi.nlm.nih.gov/2014/06/19/what-is-the-difference-between-a-substance-and-a-compound-in-pubchem/.

Please follow https://pubchemblog.ncbi.nlm.nih.gov/2014/06/19/what-is-the-difference-between-a-substance-and-a-compound-in-pubchem/.