Glossary
FDM
FDM is the most common home 3D printing process, building parts by melting plastic filament and depositing it layer by layer.
FDM, short for fused deposition modeling, is the 3D printing process used by nearly every affordable home printer. A motor pushes solid plastic filament into a heated nozzle, where it melts and gets pushed out in a thin line. The printer moves that nozzle, and often the bed, in the X, Y and Z axes, tracing one flat layer at a time until the shape builds up from the bottom.
FDM matters because it decides which filaments, printers and troubleshooting steps apply to your project. It handles PLA, PETG, TPU and similar plastics well, and it can print functional parts, brackets and enclosures without much post-processing. Compared with resin printing, FDM produces visible layer lines and slightly less fine detail, but it is cheaper to run, less messy and easier for a beginner to keep at safely.
When shopping for an FDM printer, look at build volume, whether the hotend can reach the temperatures your filament needs, and how much bed leveling is automated versus manual. Common beginner mistakes include picking a printer that only handles PLA when the plan is to print PETG or TPU later, and ignoring first layer quality because it seems like a small detail rather than the main cause of failed prints.