There are quite a few different material option available for FDM 3D printing. Each ranging from durability to flexibility to price, to ability to print. Two most commonly used materials are PLA and ABS.

PLA (Polylactic Acid)
PLA is biodegradable (non-toxic) material (under the correct conditions) thermoplastic derived from corn starch and the most cost effective material to print. It works for wide variety of 3D printing applications because of ease of use. PLA is not as sensitive to temperature changes. Parts printed with PLA have great surface quality. While PLA has very high tensile strength. Its low elongation and can deform at 120oF, make it a very brittle material at ploughing field. This is why PLA is not suitable for parts that will undergo a lot of wear and tear or being expose to elements for long period of time. It has small shrinkage rate, making it perfect for large parts molds and prototypes.

ABS (Acrylonitrile Butadiene Styrene)
ABS is much more mechanically strong material due to its high glass transition temperature and bend before breaking. ABS is toxic material  It is more tricky to print with, because it is more sensitive to temperature changes in the environment. That why it need a full inclusion and heated bed plate. ABS needs to cool slowly, otherwise if it cools too rapidly your ABS print can crack along layer lines. Also ABS prints are much more susceptible to curling and warping during the printing process. In general ABS can withstand more heat pressure and stress better than PLA making a much more suitable plastic for wear and tear applications. Legos are made of ABS and this is go to material for the majority of mechanical applications. ABS can also be acetone vapour finished since it is soluble in acetone. The process cost more but it would make your part much more water like surface and give shine which it comparable to injection mold quality. Neither PLA or ABS are flexible plastic, ABS will distort and bend before breaking. While is more brittle and will break under stress. PLA can handle more weight before breaking.

Polyethylene terephthalate (aka. PET, PETE, PETG) is a plastic resin of the polyester family that is used to make beverage, food and other liquid containers, as well as for some other thermoforming applications. Its similar strength property as ABS yet it more chemically resistant and extreme high strength filament and can achieve very sturdy and strong prints. It has very low shrinkage, making this perfect for larger flat surfaces. It’s more flexible than PLA or ABS. PETG is also very strong, it’s not brittle but can be scratched more easily than ABS which is harder. PETG is a clear amorphous thermoplastic that can be injection molded or sheet extruded.

Polycarbonate ABS, which can handle much high glass transition temperature than ABS.

Nylon, quite strong and some even FDA approve
Carbon fibre reinforce nylon
Wood
Thermoplastic Polyurethane (TPU)
Metal
Glow-in-the-dark
Polyvinyl alcohol (PVA)

Available at Advanced Precision Lab Malaysia-Japan International Institute of Technology ( MJIIT)

The Pro2 model is a true successor to the previous Raise3D model, the N2. This dual extruder 3D printer with an enclosed print area is designed to print multiple materials and heat sensitive materials to perfection.

The Electronic Driven Lifting is Raise3D’s new dual extrusion system, which is unique in the Pro2 series. It refers to the technology used to switch from nozzle 1 to nozzle 2, while printing. The way this system works is one of the most fluent dual systems we have worked with to date. Read more

3D printing describes a wide array of different technology that all similar but do it in different way. The various types of 3D printer are describes below.

1.   Vat Photopolymerization
Laser-based stereolithography (SLA) and digital light processing (DLP) 3D printing
The first 3D printing process created- vat of liquid that turn solid when it exposed to UV light in selective ways and pulling that print out change it light layer by layer to make sure its create each layer of the object as pulling out. There are couple of different ways to this but they all falls under the same basic idea. There are used by couple of different companies. It allow for super high details models that are absolutely beautiful. However it does has couple of disadvantageous.
1. Only used single type of material.
2. UV curing polymer sometimes it hard to work with and can be a little bit toxic.
3. Material a little bit expensive.

2.  FDM-Fused Deposition Modelling (or Fused filament fabrication-FFF 3D printing)

The mist ambiguities 3D printing available.
Mature technology and many company used it for years.
High end machine quite amazing with it.
Can use a variety of materials and many of them are very cheap in cost.
Some FFF 3D printer can print more than one material.
Overall FFF 3D printer is super cool and

3.  Material Jetting
Head likes inkjet printer turn liquid to solid immediately using UV curing, heat curing and deposited layer by layer.
Few company build it and very expensive.

4.  Binder jetting
Thin layer dusk and binder act as glue.
Can be full colour.
Don’t have to worry of support.
It’s very large -need reservoir and very messy with messy dusk
More expensive technology and few company have control over the pattern.
the layer very high resolution.

5.  Powder bed fusion
The same idea of binder jetting.
Powdery substance and bind it to itself or used laser to melt and harden.
can create part that so strong
High power laser and expensive.
the layer very high resolution.

6.  Direct energy deposition
Kind of new technology- basically is welding in 3D
Filament of metal and melt it and create in 3D.
Very strong part
Imprecise and rough and not high details.
Need to mill the edge to create smooth surface.

7.  Sheet lamination
Laying down a sheet of paper and cut it out with the shape by using cutter and glue it and laying down another piece of paper-cutting out that layer-glue it. Layer by layer building up the object.
Can create full colour print and absolutely beautiful.
Look like a particle board and solid.
Clean and easy to use

3D printing is any of various processes in which material is joined or solidified under computer control to create a three-dimensional object,[1] with material being added together (such as liquid molecules or powder grains being fused together). 3D printing is used in both rapid prototyping and additive manufacturing (AM). Objects can be of almost any shape or geometry and typically are produced using digital model data from a 3D model or another electronic data source such as an Additive Manufacturing File (AMF) file (usually in sequential layers). There are many different technologies, like stereolithography (SLA) or fused deposit modeling (FDM). Thus, unlike material removed from a stock in the conventional machining process, 3D printing or AM builds a three-dimensional object from computer-aided design (CAD) model or AMF file, usually by successively adding material layer by layer.[2].  Read More from wikipedia