As verbs the difference between foster and promotes
is that
foster is to nurture or bring up offspring; or to provide similar parental care to an unrelated child while
promotes is third-person singular of promote.
As an adjective foster
is providing parental care to unrelated children.
As a noun foster
is a forester.
As a proper noun Foster
is {{surname|A=An|English|from=occupations}}, variant of Forster.