Hi! Thank you. It is indeed my pleasure to help.
A screenprint is sort of like a poster, except not. The difference is that each screenprint is individually hand-printed using a sort of mesh screen stencil through which ink passes onto high-quality archival paper, whereas posters are made by mass reproduction of an image onto paper by a printer. Screenprints are typically considered to be collector’s items, especially when they are hand-numbered like the ones available through the exclusive Babel presale on Mumford & Sons’ official website. Those screenprints will not be available anywhere else and are “strictly limited edition.”
You can click here to watch one process by which screenprints are created. You’ll see that only one screenprint and one ink color can be printed at a time so, with any screenprint that requires more than one color, it will have to go through the screening and drying process at least once per color. It’s easy to see why screenprints are far more valuable than posters.
I hope this gives you the information you need!