Engineers design materials, structures, and systems while considering the limitations imposed by practicality, regulation, safety, and cost. The word engineer (from the Latin ingeniator) is derived from the Latin words ingeniare ("to contrive, devise") and ingenium ("cleverness"). The foundation education of an engineer is typically a 4-year bachelor's degree in an engineering discipline plus 4-6 years peer reviewed professional practice. The work of engineers forms the link between scientific discoveries and their subsequent applications to human needs and quality of life.