RED Dragon
The RED Dragon is a sensor. Originally it was 6K, but then RED took it all the way up to 8K, but since then decided to scale it back down to 5K, but not before improving and rebranding the Dragon 8K into the Monstro. That sentence sounds awful, but that’s because it’s an accurate layman summary of the RED Dragon sensor history over the past decade.

RED camera and product history
So, now you know the new RED camera lineup details and you’re ready to make a purchase or rent for your next project, but then you see that the RED Raven is actually cheaper than the Dragon-X kit. Then you start to wonder about used RED cameras, or the RED Weapon 8K. What about the Scarlet-W your film school buddy has, or the RED Epic?

Suddenly, you start to wonder who would win in a fight between a Dragon and an Epic but then you remember one is a mythical creature and the other is just a cool name for a really long poem.

How can you possibly know which RED camera is the best? Furthermore, how can you know which is a camera vs a sensor vs an integrated kit? Let’s quickly define some RED camera terminology:
RED One
The RED One is a camera body, brain, and sensor. It’s the entire camera system, and the first production camera introduced by RED in 2007. They later offered upgrades to a 14-megapixel sensor called the “M-X”.

The RED One is said to have effectively the same quality as 35mm film, though most filmmakers looking for a “film look” will prefer the image received from an ARRI camera like the Alexa.

RED Epic
The RED Epic is a camera body/brain. It came after the RED One, and originally featured the M-X sensor, but then offered the Dragon sensor, and you can now upgrade your Epic to the Helium and Gemini sensors. The Epic was the higher-end version of the first DSMC body/brain, and it has higher frame rate capability when compared to the RED Scarlet.

RED Scarlet
The RED Scarlet is a camera body/brain. It was built to compete with cameras like the Canon C300 and had fewer capabilities than the RED Epic. In 2015 RED made the Dragon 5K sensor available for the Scarlet as well, but that was a “downgrade” from the RED 6K Dragon from 2013.
RED Dragon
The RED Dragon is a sensor. Originally it was 6K, but then RED took it all the way up to 8K, but since then decided to scale it back down to 5K, but not before improving and rebranding the Dragon 8K into the Monstro. That sentence sounds awful, but that’s because it’s an accurate layman summary of the RED Dragon sensor history over the past decade.

source : https://www.studiobinder.com/blog/red-digital-cinema-camera/