Precedent is binding if a higher court has made a decision or interpretation that a lower court must follow.
Stare decisis is where a court maintains the status quo - that is, it reaffirms a previous decision or bases a new decision its own prior decision.
For example (I apologize if this example addresses a touchy subject, but you will cover it in Con Law.)
In Planned Parenthood v. Casey, the US Supreme Court had the opportunity to address Roe v. Wade, which held that state restrictions on abortion during the first two trimesters of pregnancy violate the 14th Amendment to the Constitution. They decided to reaffirm Roe's central holding, basing their decision in large part on stare decisis. This is not because the precedent was binding - the US Supreme Court can overrule itself.
Casey also held that states may not place undue burdens on the right, and that requiring spousal consent is an undue burden. Therefore, requiring spousal consent violates the Constitution. This is binding precedent on any lower court and government agency. A Federal Court of Appeals must hold that requiring spousal consent is unconstitutional.
Regarding the example of previous states. If one state makes a decision about its own state law or on federal laws, and uses another state's decision as authority, that is an example of neither binding precedent nor stare decisis. It just means that it found that state court's analysis persuasive.
However, sometimes state X will have to make a ruling on state Y's law, and they must use state Y's interpretation of the law. But that's a choice of law issue that you may or not cover in Civil Procedure.