Just to enrich the answers,
Hierarchic axis-parallel decision-trees are fast (CART, C4.5) but there are other alternatives such as non-hierarchic decision trees or those that perform oblique partitions that are not, although they can be more accurate. Check the following references if you are interested (They are not an exahustive selection).
Grubinger, T., Zeileis, A. and Pfeiffer, K.-., 2014. Evtree: Evolutionary learning of globally optimal classification and regression trees in R. J.Stat.Software 61 (1), 1-29.
Murthy, S.K., Kasif, S. and Salzberg, S., 1994. A system for induction of oblique decision trees. J. Artif. Intell. Res. 2 (1), 1-32. http://dx.doi.org/doi:10.1613/jair.63.
Cantú-Paz, E. and Kamath, C., 2003. Inducing oblique decision trees with evolutionary algorithms. IEEE Trans. Evol. Comput. 7 (1), 54-68. http://dx.doi.org/10.1109/TEVC.2002.806857.
Heath, D., Kasif, S. and Salzberg, S., 1993. Induction of oblique decision trees. J. Artif. Intell. Res. 2 (2), 1002-1007.