A more thorough explanation:

The alternative-means doctrine is a principle in criminal law that states when a crime can be committed in more than one way, the jury must be unanimous on the defendant's guilt but need not be unanimous on the possible different methods of committing the crime, as long as each possible method is supported by substantial evidence.

Let's say a defendant is charged with the crime of arson, which can be committed in two ways: by setting fire to a building or by using an explosive device. If the evidence presented at trial supports both methods, the jury does not need to agree on which method the defendant used to commit the crime, as long as they all agree that the defendant is guilty of arson.

This doctrine is important because it allows for more flexibility in the jury's decision-making process, while still ensuring that the defendant's guilt is proven beyond a reasonable doubt.