yes, aluminum frame, steel rear triangle. This particular bike is a low end walmart junker. All the boxmart suspension bikes copy the look of real suspension bikes but sure don't work well. They typically a sticker that reads "not for off road use or stunts", or that is in the owners manual. Most of the stock forks are just coil springs inside with no dampening device other than sticktion. Heavy and flexy and just don't do much. The frame shocks are the same, coil over stiction. It's quite easy to bottom out the travel and hear the loud bang when the ends meet. just riding off a curb can max out the travel.
In keeping the price down, they have stamped sheet metal hubs and cups, low grade steel throughout and just bad assembly with little to no lube. Chains, gears, ders, cables and brake arms that will rust in just a few months. Most are worn out in 500 miles.
There are some pretty decent full suspension bikes. My 'good' bike is a Specialized Stumpjumper FSR. $2k in 2002. I didn't care for the stock fork so that was another $750 fork. It still rides great. The fork has locked up on me, that model was prone to vapor lock, so it needs occasional service. It is air compression with valved oil dampening. The frame shock is air compression with valved air dampening. The full suspension concept started in with the first safety bikes in the 1870s, back before any roads were paved. The mtb boom starting in the 1980s saw some pretty strange suspension designs, some just bad or very unreliable. Lots of experimenting using the customers as test pilots. It took about 20 years for the industry to get it right. A new Trek or Specialized mtb will ride very well. If you want to get in to dirt trail riding, don't risk yourself on walmart junk.
Old rigid mountain bikes are quite good for urban bikes, especially in areas with horrible streets (here). Wide street tires will speed them up and still be able to handle potholes, cracks, patches, seams, curbs, limestone trails, etc. With big enough tires you don't need shocks for urban use.
Years ago, I had a Cannondale Super V 3000 (or similar) in for rebuilding with a pipe as frame shock replacement. The bike was nearly unrideable with the front shock still working. The back wheel kept lifting off the pavement which usually sends you flying sideways. That's where i got the idea for this pipe but I put on a rigid fork to keep it workable.