Macro-evolution is a term sometimes used in a scientific concept, but more often thrown around by creationists to get around some of the instances in which evolution has been observed. Macro-evolution means evolution on a large scale, while micro-evolution means evolution on a small scale. A common creationist claim is that micro-evolution has been observed, but macro-evolution never has.
In science, however there is no clear dividing line between the two. To the extent that "micro-evolution" is a recognized term at all, it generally means change within species, while macro-evolution means change between species. Unfortunately for creationists, speciation has been observed in laboratory conditions -- scientists have successfully induced the evolution of new species that cannot breed with the original strains.
Creationists weasel around this inconvenient fact by talking about "macro-evolution" not in terms of species but in terms of "kinds." But a kind is not a scientific notion, and creationists are notoriously vague when it comes to defining what it means. For instance, is a chihuahua the same kind as a Saint Bernard? How about a chihuahua and a dire wolf? What about a wolf and a house cat? They're both mammals and both in the carnivora family. In science, there is no clear dividing line between kinds beyond species (and even species can be a fuzzy term).
So creationists cannot agree on what "kind" means -- except in the ad hoc sense that whenever it can be agreed that evolution is solidly proved between two species, they must not be the same kind.}}