A more thorough explanation:

A legal vote is a vote that is cast in the proper form and manner for an eligible choice by someone entitled to vote. It is the expression of one's preference or opinion in a meeting or election by ballot, show of hands, or other type of communication.

• A person who is registered to vote casts their ballot for their preferred candidate in a presidential election. This is a legal vote.
• A person who is not registered to vote attempts to cast a ballot in a local election. This is an illegal vote.
• A person who fills out their ballot incorrectly, such as by marking more than one candidate for a single position, casts a spoiled ballot which is not a legal vote.

These examples illustrate the definition of a legal vote by showing the different scenarios in which a vote may or may not be considered legal. A legal vote is one that is cast by an eligible voter in the proper manner and for an eligible choice.