This is a Plumeria tree. Other common names include: frangipani, riods, temple tree and many named cultivars. Plumeria is generally a small tree growing to about 30 ft high. The species and hybrids vary somewhat in tree size, compactness, and branching character, leaf and flower size and color, and some drop their leaves at certain times of the year. I am not sure what variety or cultivar you have. The tree likes full sun and grows best in well-drained slightly acidic soil. For additional information and details on Plumeria please visit http://www.ctahr.hawaii.edu/oc/freepubs/pdf/OF-24.pdf.