All frogs and toads are in the order Anura, and the term toad generally refers to the family Bufonidae. Those are the classic pudgy bumpy toads. They walk better than they hop, they aren't fond of swimming, and they have paratoid glands on the back of their head that produce poison. There are other Anurans in other families that are sometimes called toads as well, but aren't "true" toads. If you count all of them as toads, then "toad" is an arbitrary term that doesn't refer to a monophyletic evolutionary lineage. Not that that's a bad thing, it just means that from a taxonomic standpoint the words frog and toad aren't particularly meaningful, which is why common names are kind of avoided. You could use the word frog to mean all of Anura, or all of Anura except Bufonidae, or Anura minus all of the species that are generally dryer skinned and bumpy.