Resembling a swarm of starlings mid-flight (like this murmuration captured on video over a river in Ireland) these tiny blue points of light are the stars that comprise dwarf galaxy ESO 540-31, located in the constellation Cetus, The Whale.
As a dwarf galaxy, ESO 540-31 contains a few hundred million stars, which may sound like a lot but is only a tiny number compared to the estimated 400 billion stars in the Milky Way alone, of which our sun is just one.
The many yellow-orange objects scattered around the image are even more distant galaxies, each in itself an entire island oasis of stars.
Source: ESA/Hubble site
Credit: ESA/Hubble & NASA. Acknowledgement: Luca Limatola