Answer:
The dark energy is one of the primary composition of the universe, which is not visible and are mysterious. as a very little is known about this energy. This dark energy makes up nearly 68% of the universe. It is often considered as a property of space. The presence of dark energy can be detected as it affects the expansion of the universe. The universe started to form right after the big bang explosion and since then the space is expanding in all direction. With this, the dark energy present in the universe also is expanding at a considerably faster rate in association with the Cosmic Microwave Background (CMB) radiation. The measurements of the distance and their connection with the redshift provided an evidence that the universe has been expanding at a certain speed.