On this site, these terms apply to software, data and other materials that are available for download.

An associated publication either announced the availability of a download or necessitated a download.  For example, it might be a publication describing a program available for download or a publication explaining a class of force fields for which we provide downloads.  That is, it is a publication directly tied to the download in some manner.

A related publication provides supporting information for the download.  For example, it might be a paper that explains the theoretical background behind a program.