This is Cep OB3b, an active hub of star-formation where astronomers can see various star types (in various stages of evolution) in one centralized location.
The cluster can be found approximately 580 light-years from Earth in the northern constellation of Cepheus. Interestingly, astronomers think the great Orion cluster may follow in the same steps as this cluster in the future, as both share many similarities.
As per usual, this is a composite image, stitched together using images taken of the cluster at different wavelengths using special filters, all taken by the 0.9 meter telescope at Kitt Peak. The individual colors are representative of said wavelengths, with blue (cyan) as the visual wavelengths, near infrared as orange, and an emission line of hydrogen represented by the red.