Accessions refer to items that become part of or are added to a larger collection, property, or entity. They are additional items that enhance or increase the value of an existing collection or property. In the context of property law, accessions can include improvements, modifications, or additions that are physically or legally attached to an existing property. For example, if a person adds a room to their house or installs new fixtures, these additions would be considered accessions as they become part of the property.