"Subjects" refers to anyone living in a specific territory or under the authority of a government. In the context of England, it refers to the citizens and residents of the United Kingdom.
"Commoners" in England specifically refer to individuals who have traditional rights to common land, which is a type of land that is owned by a group of people in common, rather than by a single individual or organization.
Commoners have certain rights to use and access common land, such grazing rights, harvesting firewood, or collecting peat, depending on the specific rights attached to the common land in question.
Commoners are not a strictly social or economic class, and people from different social and economic backgrounds can be commoners.