Windows does not have a native "Merge" button built into File Explorer, so you will need a third-party application. PDF, PS and DjVu - ArchWiki
PDF Arranger — Helps merge or split pdf documents and rotate, crop and rearrange pages. It is a maintained fork of PDF-Shuffler. Merge PDFs for free - Combine PDF files online - Adobe merge+pdf
Merging documents isn't just about tidying up your desktop; it significantly improves workflow and collaboration. Windows does not have a native "Merge" button
The Ultimate Guide to Merging PDF Files: Tools, Tips, and Best Practices and Best Practices
