Serif Affinity Publisher 2.0.3.1688 Best Full Versio...

: Select File > New to choose your page size (e.g., A4, Letter). Set your Margins to ensure text doesn't get too close to the edge and include a Bleed (usually 3mm) if your design has colors or images that go off the edge of the paper.

: This seems to be the version number of the software. Software versioning typically follows a major.minor.patch.build numbering scheme: Serif Affinity Publisher 2.0.3.1688 Full Versio...