Biostatistics, most generally, is the application of statistics to biology and, most commonly, to medicine. Because research questions in biology and medicine are various, biostatistics has expanded its domain to include any quantitative, not just statistical, models that may be used to answer these questions.
Programs in biostatistics are almost exclusively post-baccalaureate (i.e., found in graduate schools). They are most often found in schools of public health, affiliated with schools of medicine, or as a focus of application in departments of statistics.
However, many universities that deal with ecological research have an biostatsitics course that introduces concepts such as hypothesis testing for univariate and sometimes multivariate data sets with one, two or more samples. Often this is combined or followed with some kind of experimental design course.
As a discipline designed to yield information, biostatistics may be considered as one (highly-developed) branch of medical informatics, which, in turn, may be encompassed by the newer field of bioinformatics.
Consequently, biostatistics draws quantitative methods from fields such as: