Terminology

Materials

ABS - Acrylonitrile Butadiene Styrene - a thermoplastic commonly used as the build material or ‘filament’ in fused deposition modeling 3D printers. It’s fairly strong, but it’s also a bit tricky to work with (and gives off nasty odors when melted). [FDM, SLA]

Alumide - Alumide is a variation of nylon that has been combined with aluminum particles. In terms of durability and physical properties, this material is very similar to nylon. The difference is found in the shiny, durable and porous surface finish. [SLS]

Conductive - relatively new addition to the filament market, conductive 3D printing materials can be used to create touch sensors in applications that require human interface devices like gaming pads, and MIDI machines. Other projects include conductive traces in wearable electronic devices and creating interfaces between computers, Arduino boards, and other components. [FDM]

PLA - Polylactic Acid - a biodegradeable plastic that’s used as the build material or "filament" in fused deposition modeling 3D printers. This material is easier to work with than ABS, and the smell is not so unpleasant, but the trade-off is that PLA is structurally more brittle.

SLA Resins - This material is particularly suited to producing large parts in a short span of time, while still maintaining a high degree of detail. There are various types of resins ranging from rigid to flexible to ceramic to dental. Some resins are even strong enough to be machined after curing. The popularity of SLA resins stems from its superior speed and accuracy. [SLA]

Nylon: The tough and durable material used for 3d printing with a tensile strength of 70,000 PSI. Needs to be properly stored since it can soak up water when it is left out in the open. Printing Nylon after it has absorbed water can lead to problems regarding print quality meaning filament storage is critical. 

Polyvinyl butyral: A specialty filament known for its ability to be layered smoothly with Isopropyl Alcohol that is useful for printing out translucent material. However, it has poor layer adhesion, inferior mechanical properties, and higher hygroscopic properties. 

Terms

Additive Manufacturing - the process of building up a three-dimensional object, one thin layer at a time. 3D printing is only one category of additive manufacturing, though the two terms are frequently considered to mean the same thing.

CAD - Computer Aided Design - these are applications to create models in either two or three dimensional formats. While CAD was initially developed for use in the architecture and manufacturing industries, consumer friendly applications are now readily available for little or no cost.

FDM [FFF] - Fused Deposition Modeling - a 3D printing process that extrudes heated thermoplastic material through a computer-controlled print-head nozzle to build parts up in layers. FDM is actually a term that’s been trademarked by Stratasys. This led to the RepRap open-source community to coin the term "fused filament fabrication" (FFF) for a more generalized and legal way to describe the process.

Filament - this is the base material that’s used to 3D print objects via fused deposition modeling. Filament is usually a thermoplastic — such as ABS or PLA — that’s fed to a print head as a solid, then heated to melting point for extrusion through a small nozzle. Filament is commonly available in spools of either 1.75mm and 3 mm diameter widths.

G-code - the language used to instruct your 3D printer to perform operations. In common usage this is almost exclusively generated by applications, and is not written by hand. G-codes control specific actions like motion, speed, rotation, depth, and other related switches and sensors used in the operation of a 3D printer.

RepRap - is shorthand for "replicating rapid prototypers", machines which are open-source 3D printers utilizing the fused filament fabrication (FFF) process. One of the defining characteristics of a RepRap machine is that it should be capable of printing out its own parts (but not necessarily all of them). Various RepRap designs and build instructions are freely downloadable from reprap.org.

SLA - Stereolithographic Apparatus - Stereolithography is a 3D printing technology that works via a process called vat photopolymerization. Objects are built in layers using a laser beam to trace out and solidify each successive layer of an object on the surface (or base) of a vat of liquid photopolymer.

Slicer - Used in additive printing that building the object layer by layer. A slicer is the application used to divide a 3D model into flat layers which are then printed one layer at a time. The output of a slicer is G-code that controls the path, speed, and temperature of the printer. Slicer applications are available in both open-source and proprietary and they’re an essential tool for successful 3D printing.

SLS - Selective Laser Sintering - a technology commonly employed by 3D printing services for metallic objects. SLS is a powder bed fusion 3D printing technique that uses a laser to selectively fuse - or sinter - together the granules of successive layers of powder.

STL - an abbreviation of "stereolithography" - a type of digital document or file that stores information about 3D models. The STL file format is the most commonly used file format for 3D printing. When used in conjunction with a 3D slicer, it allows a computer to communicate with 3D printer hardware. The STL file describes only the surface geometry of a three-dimensional object without any representation of color, texture or other common model attributes. STL files are usually generated by a computer-aided design (CAD) program, as an end product of the 3D modeling process. “.STL” is the file extension of the STL file format.