Often times when talking about custody people use the terms "full custody" or "sole custody" in discussing a custody arrangement in Indiana. These are incomplete terms. In Indiana, there are two concepts regarding custody, "legal custody" and "physical custody."
Legal custody is the concept of who makes decisions for children including but not limited to where a child goes to school, what to do about their religious upbringing, and medical care. Physical custody refers to where a child lays their head on most nights. There is typically a primary physical custodian/custodial parent and a non-physical custodian/non-custodial parent.
Whether in divorce or paternity matters, courts in Indiana apply a "best interest" standard when evaluating custody issues. While it may seem simple to say that a court is going to do what is in the best interest of children, that can be complicated when both parents believe that they have the best interest of a child at heart and those ideas are not consistent with each other. Under I.C. 31-17-2-8, there are statutory factors that the court will consider to determine what is best for a child including, the age and sex of the child, the wishes of the child's parent or parents, the wishes of the child, with more consideration given to the child's wishes if the child is at least fourteen (14) years of age, the interaction and interrelationship of the child with parents, siblings, or other family members, the child's adjustment to home, school, and community, the mental and physical health of all individuals involved, and evidence of a pattern of domestic or family violence by either parent.
Those factors are important and they must be supported by evidence properly admitted for a judge to consider. It is important to understand that simply believing you have your child's best interest at heart, while true, is not sufficient for the court to make a determination.