My understanding of the terms are that if you have a natural product N, and you follow the synthetic pathway A + B -> C -> F -> N, where A, B and all the reagents required can either be bought, or made from the literature (not necessarily the exact reagents, mind, but perhaps analogues too, so if an ethyl ester is described but you need a methyl ester, that's fine) then that's a total synthesis.
A formal synthesis would be finding an alternative pathway to C or F in this instance, but not necessarily completing to N. Look into the recent Woodward quinine synthesis story for some more information, perhaps.
S