The purpose of this review is to describe the new DNA sequencing technologies referred to as next-generation sequencing (NGS). These new methods are becoming central to research in human disease and are starting to be used in routine clinical care.Advances in instrumentation have dramatically reduced the cost of DNA sequencing. An individual's entire genome can now be sequenced for $7500. In addition, the software needed to analyze and help interpret this data is rapidly improving. This technology has been used by researchers to discover new genetic disorders and new disease associations. In the clinic, it can define the etiology in patients with undiagnosed genetic disorders and identify mutations in a cancer to help guide chemotherapy.Here we discuss how whole-exome sequencing and whole-genome sequencing are used in basic research and clinical care. These new techniques promise to speed research and affect how healthcare is delivered.