In Batman v Superman: Dawn of Justice, audiences were introduced to metahumans in the DC Extended Universe. This happened when Batman got a hold of Lex Luthor’s secret computer files that revealed them. The introduction was vague and left many things unanswered. Now were given a breakdown of what the metahuman is. In the BvS 101 video it explained how the term metahuman is any figure on Earth who has superpowers. One thing metahumans have in common is they can be either good or evil, or a mixture of both. One good group of metahumans is the Justice League. The good metahumans are: Wonder Woman, Superman, Aquaman, The Flash, and Cyborg. The other metahumans to be introduced in the DCEU aside from the Justice League are Shazam, and Green Lantern.
— Batman v Superman (@BatmanvSuperman) June 14, 2016