How does 3D printing actually work?
Imagine stacking very thin sheets of paper on top of each other to form an object. 3D printing follows the same principle: a printer deposits material (often molten plastic) in ultra-thin layers, generally between 0.1 and 0.3 mm thick. Each layer solidifies, and then the next one is placed on top of it, until the complete object is formed.
Main technologies
The most common technology for individuals is FDM (Fused Deposition Modeling): a plastic filament is heated and deposited by a nozzle that moves according to the design of each layer. But there are also other techniques using liquid resin hardened by laser, or even fused metal powder.
Applications
3D printing is used in many fields: industrial prototyping, manufacturing of spare parts, creation of customized objects, medical prostheses, architectural models, figurines, tools... You can print plastic, metal, ceramics, and even organic materials for certain medical applications.
The major advantage is the freedom of creation: you can manufacture complex shapes that are impossible to achieve with traditional methods, and produce a unique object without the need for an expensive mold.

