Instructions given to a jury both verbally and typically in writing, often with a verdict form. The jury instructions typically lay out the elements of each claim in the case and what each party has to show to meet their burden of proof. It is in effect a set of instructions as to how to consider the evidence.
Many of the US appellate circuits have published model jury instructions for each type or class of cases, and these are a useful tool when preparing cases and assessing whether a case is winnable or not.