The latest "conversion" trend is moving away from the original binary WAD structure to (Universal Doom Map Format). Tools like Zwadconv (by Randy Heit, creator of ZDoom) convert older Hexen-format maps to UDMF, which allows for 3D floors, slopes, and unlimited sector tags. Think of it as converting a VHS tape to 4K Blu-ray—the same movie, but with infinitely better capabilities.
You will see a list of lumps (Entries). MAP01 , THINGS , LINEDEFS , SIDEDEFS , etc. wad converter
Old source ports (like vanilla Doom.exe) have strict limits (Visplane overflow, sprite limits). A converter can "downgrade" a modern map to run on DOS-era hardware. The latest "conversion" trend is moving away from