A more thorough explanation:

Definition: Plebiscitum (pleb-si-tuhm) is a term from Roman law that refers to an enactment passed by the assembly of the common people (the concilium plebis) at the request of a tribune. It was a way for the plebeians to make laws that applied to the whole community, including the patricians.

Examples: The Concilium Plebis was an assembly of the plebs that gathered together to enact legislation. It was presided over by a tribune of the plebs and was active from early times. The resolutions of this assembly, called plebiscita, were often binding on the whole community and were regarded as laws.

For example, in 494 B.C., tribunes of the plebs were created to protect individual citizens from oppression. They had the right to hold meetings of the Concilium Plebis, which eventually became identical with the Comitia Tributa. The resolutions of this assembly, plebiscita, at first bound only the plebeians, but eventually came to be binding as laws on the whole people, patricians and plebeians alike.

Another example is the Lex Hortensia of 287 B.C., which culminated in the passing of a law that made plebiscita binding on the whole community. This law was a significant development in Roman law and helped to establish the power of the plebeians in the Roman Republic.