One object, many processes
A painting, drawing, or unique sculpture is usually one of one. A print can also be an original work when the artist creates the image through etching, lithography, screen printing, woodcut, monotype, or another print process.
A reproduction begins with an existing artwork and copies its image. That does not make it worthless, but it is different from a print conceived as the artwork itself.
Read the edition information
For editioned photography, digital art, and prints, look for the total edition size, the number of the specific impression, the artist's signature, paper or substrate, and any artist proofs.
A smaller edition is not automatically better. The artist's practice, the quality of production, condition, provenance, and the strength of the image remain more important than a low number alone.