The first inexpensive commercial cameras were box cameras. Next came the folders. Both really did not give you a proper view of what you were taking a pictuce of. Thus the TLR camera. The Twin Lens Reflex. Had two identical lens. One was for taking and one was for viewing. Often the viewing lens was a bit cheaper (no multicoating etc).
With a TLR you saw mostly the same image the film would. The image would be reversed. But there was no moving mirror etc like in the SLRs.
Most all TLRs used roll film such as 120 to 620 film. The 120 is still available. I have a trio of TLRs to show. The Kodak Duaflex IV is a fixed focus 620 film camera with included external flash. It was sold from 1955 to 1960 with a suggest retail price of $24.50. I my mom bought it for me from a thrift store for $5.00 in original box. 620 film is not available but 120 film can be rewound on 620 spools.
The Argus 75 is another fixed focus 620 film TLR. It was produced beginning in 1958 to 1964 and thus a direct competitor to the Kodak Duaflex. Both were US made.
The last is a Pearl River Chinese made knock off of a Roleflex. It uses 120 film instead and actually is a varible focus. It was just recently given to me. I believe all 3 have 75mm lenses. Hence theoretically the pictures should be similar.