A more thorough explanation:

An appellant is a person or party who is not satisfied with the decision made by a lower court and wants to challenge it in a higher court. The appellant files an appeal to request the higher court to review and possibly overturn or modify the lower court's decision.

For example, if John sues Mary and the court rules in favor of Mary, John may file an appeal to a higher court. In this case, John is the appellant, and Mary is the appellee. If the higher court agrees with John's appeal, the case may be sent back to the lower court for a new trial or a different outcome.

It's important to note that the appellant must have valid grounds for appeal, such as errors in the lower court's procedures or evidence that was not considered. The appellant must also follow specific procedures and deadlines for filing an appeal.

In summary, an appellant is someone who appeals a lower court's decision to a higher court, seeking a different outcome.