Generally, an appeal is a review of a lower court's decision by a higher level court.  The defendant has a right to appeal in a criminal case.  The defendant must file within a required time period to preserve the defendant's right to appeal.  In order to preserve the issue for the appeal, a proper motion or objection must be made at the lower court level unless the error is either plain or fundamental error.

The appellant is the party seeking review by the appellate court of the error(s) in the lower court.  The opposing party is the appellee.  The appellant must file the initial brief within a specific time period.  A brief is the legal document which states the issue(s) appealed with supporting facts and law.  Once the brief is served on the appellee, the appellee must file a brief in response within a specific time period.  Then, the appellant may file a brief in reply to the appellee's response within a specific time period.  If the appellate court feels that oral argument will aid in the decision making process, then oral argument may be heard.  Generally, a three judge panel will rule on the issue(s).  In rare instances, the Supreme Court will grant review of an appellate court's decision.

An appeal can become very expensive for the client.  Before appealing a court's decision, the criminal defense attorney should discuss with the client whether there would be a practical benefit to initiating an appeal.