Pen plots are unlike traditional prints; each one is subtly different due to the interaction between the pens used, ink and paper.
To further complicate/improve things, with traditional printing "Limited Editions" are identical prints, designed to be as close to the original as possible. However, with generative art, each plot is unique due to randomness in the algorithm.
"Open Edition/Series" means there is no limit to the number that will be produced, but each one will still be unique and different.
"Limited Edition" refers to a limited number of plots within a series and/or colourways and size, and again each one will be different.
"Static" is used when each plot in a series will be the same without any randomness, this is normally found in the "Sacred Geometry", but I haven't posted any yet.