Trailers with metal siding are called Stick and Tin construction since theyou are wood-framed and have aluminum siding. They will be heavier.
Trailers with Filon-sided walls have aluminum frames. The Filon-sided is a bonded sandwich construction. They will be lighter than their wood framed counterparts.
Both types have their advantagesite and disadvantages.
Dan- Firefighter, Retired:C, Shawn- Musician/Entrepreneur:W, Zoe- Faithful Golden Retriever(RIP:(), 2014 Ford F150 3.5 EcoboostMax Tow pkg, 2016 PrimeTime TracerAIR 255 w/4pt Equalizer and 5 Mtn. bikes and 2 Road bikes