Final answer:
The Piper PA-34 Seneca is differentiated from the Beechcraft Baron by its T-tail design, which is a significant external feature setting the two aircraft apart.
Step-by-step explanation:
One of the main features that differentiates the Piper PA-34 Seneca from the Beechcraft Baron is the T-tail design. The Seneca features a T-tail, which is where the horizontal stabilizer is mounted on top of the vertical stabilizer, creating a 'T' shape when viewed from the front or rear. This is in contrast to the conventional tail design of the Beechcraft Baron. Other differences may include variations in performance specifications, interior design, and equipment, but the T-tail is a distinctive external feature that sets the Piper PA-34 Seneca apart from the Beechcraft Baron.