A more thorough explanation:

The Abstractions Test is a way to determine if a work of art or literature has been copied from another work. It compares the actual substance of the two works to see if they share the same abstract ideas or if the substance has been copied.

The Abstractions Test was first introduced by Judge Learned Hand in the case of Nichols v. Universal Pictures Corp. in 1930. It is not a bright-line test, but rather an approach to discerning the boundaries of protectable expression by isolating and comparing each level of abstraction in the two works, from the lowest (most detailed) to the highest (most conceptual).

For example, if a writer creates a story about a young wizard attending a school for magic, and another writer creates a story about a young witch attending a school for magic, the Abstractions Test would compare the substance of the two works to see if they share the same abstract idea of a young person attending a school for magic, or if the substance has been copied.

Another example would be if a musician creates a song with a specific melody and lyrics, and another musician creates a song with a similar melody and lyrics. The Abstractions Test would compare the substance of the two songs to see if they share the same abstract idea or if the substance has been copied.

The Abstractions Test is an important tool in determining if a work has been copied or if it is an original creation.