As a young litigator, you likely are accustomed to drafting and responding to motions and memoranda on dismissal, summary judgment, discovery issues, and other issues that arise before trial. Not much tops the feeling of successfully obtaining summary judgment for your client or otherwise winning a motion or an argument. If those orders are appealable, however, you may end up on the receiving end (or if unsuccessful, the filing end) of a notice of appeal. If you are not in a firm with an appellate department, or sometimes even if you are, you may be asked to draft the appellate brief.
Tackling an appellate brief is much different from your familiar ground at the trial level. Not only is the style of argument different, but also very specific, and arguably unintuitive appellate rules govern every step of the way. Additionally, appellate judges approach an appeal differently from how a trial court approaches a motion. As such, you need to be ready to handle this new animal called an appeal.