This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
At some point prior to the late 22nd century, the 10-C reached such a level of technological advancement that they were able to construct Dyson rings around their star. However, around the late 22nd century, their homeworld was rendered uninhabitable to them as a result of cataclysmic meteor impacts. Some members of Species 10-C were able to evacuate, but many were stranded on their planet and killed. By 3190, the 10-C had created a hyperfield that served to protect them from danger. This hyperfield required boronite to be powered, which was harvested through the use of the DMA.
The 10-C became known to the Federation in 3190 when the DMA began destroying numerous star systems in order to mine boronite. At first it was believed that the DMA was a natural phenomenon, but after further study it was determined to have been artificially created. Federation Security provisionally named the race behind the DMA's creation Unknown Species 10-C, and speculated that this race may have been the Metrons, Nacene, the Q, or survivors from the Iconian Empire. (DIS: "The Examples") However, it was later determined that Species 10-C was extra-galactic in origin, ruling out some of the aforementioned species as possibilities (DIS: "Stormy Weather"), and after first contact was made, it was discovered that the 10-C were a previously unknown species and not any of the possible races listed by Federation Security.
Later, Zora was able to determine the point that the DMA entered the galaxy, which was possibly the location of Unknown Species 10-C. (DIS: "...But to Connect") Upon investigating that region, the USS Discovery found a void absent of black body radiation large enough to hold a small star system. Based on this, sensor logs were analyzed and showed that Unknown Species 10-C were using the DMA to mine boronite. (DIS: "All In")
Species 10-C are extremely large and appear to be adapted to living in the atmosphere of gas giants. This was first determined when an away team to Species 10-C's original homeworld examined skeletal remains of Species 10-C. (DIS: "Rosetta")
After initiating first contact, Doctor Hirai scanned a member of Species 10-C and determined that they have visual receptors, pheromone glands, and that they may possess auditory or electrical sensors. The 10-C used these pheromone glands and light emissions/visual receptors to communicate with each other. (DIS: "Species Ten-C")
The 10-C may have taken special care to protect their offspring, as evidenced by the ruins of a large structure that may have been used as a nursery and as a protected area for infants on their original homeworld. (DIS: "Rosetta")
Unlike many of the sentient species native to the Milky Way Galaxy, the 10-C did not have a spoken language. Instead, their language was formed by emitting emotion-conveying hydrocarbons, as well as flashing lights on their bodies to communicate how the hydrocarbons should be understood. (DIS: "Species Ten-C")