For the most part, a facial toner and a tonic are generally the same idea just called by a different name (usually instructed to use after cleanser and before moisturizer).
It really depends on the product and the brand/company labels their items. For instance, Shiseido labels what some call a toner as a softener. Clinique labels them as a lotion. Ole Henriksen indicates it as a tonic. All of these items are categorized in the Sephora catalog as Toners.
Hope that helps.