The term "target population" refers to a specific group of individuals who share similar characteristics and are identified as the intended audience for a product, advertising, or research. In the context of OBG, the target population can refer to different groups depending on the specific focus of the research or intervention. For example, one study may define the target population as resident women aged 50-64 who are eligible for screening, while another study may define it as individuals who can benefit from healthy timing and spacing of pregnancy (HTSP) messaging. In general, the target population is the group that a program or intervention is designed to serve. It is important to clearly define the target population in order to ensure that the research or intervention is appropriately targeted and effective.