Either before or after the closing arguments by the lawyers, the judge will explain the law that applies to the case to you. This is the judge's instruction to the jury. You have to apply that law to the facts, as you have heard them, in arriving at your verdict. You must consider all of the instructions and give them equal consideration.
Keep in mind that you must follow the law as the judge states it to you. If the judge gives you an instruction that seems different from what you read here or another instruction given at another trial, you must accept the instruction given by the judge of the case you are deciding as correct and be guided by the judge's statement only. Be sure to ask questions if you don't understand.