In the following video, 3D printing specialist Steve Heller asks Terry Wohlers, President of Wohlers Associates, which puts out the Wohlers Report 2014, to explain the difference between two leading metal 3D printing technologies: direct metal laser sintering, or DMLS, and electron beam melting, or EBM.

On a high level, both DMLS and EBM are additive manufacturing processes, meaning they build objects layer by layer from a variety of metal powders. The major difference between the two is that DMLS uses a laser and EBM uses an electron beam to melt and fuse layers of metal powder together in the shape of the desired object. As Wohlers explains in the video, there are advantages and disadvantages to both technologies.

In terms of the investing landscape, 3D Systems' (NYSE:DDD) direct metal 3D printers employ its own variant of DMLS, and Arcam (NASDAQOTH:AMAVF) is the sole provider of EBM. Ultimately, the more that investors can understand about the differences between DMLS and EBM and how they're primarily used, the better they can understand the market opportunity that 3D Systems and Arcam are pursuing.

A full transcript follows the video.

Steve Heller: Moving forward, in terms of metal 3D printing advancements, you've been quoted before saying how it's come [further] in 10 years than [plastic has in] the almost 30 years that plastic has been around commercially, since 1988.

I was wondering, in terms of the development cycle, in terms of technology going forward, what you see for the prevailing technology. Direct metal laser sintering seems to be the most preferred technology, with General Electric 3D-printing their LEAP engine fuel nozzle with the technology.

Electron beam melting seems to be more applicable for the orthopedic implant area. I was wondering if you could give me any comments on that.

Wohlers: Yes, metals have taken off. We believe, based on our research for our report that we do annually, Wohlers Report 2014, that the metals industry grew -- this would be additive manufacturing metals -- grew by more than 75% last year. Why is that? Because these companies are developing business cases, and they're qualifying and certifying these parts for flight, for orthopedic implants.

You're right, there are two broad classes of machines. One uses a laser to heat and melt powder, and the second is an electron beam energy source, to do the same thing: very similar process, similar powder, but different energy source.

There are pros and cons to each. The advantage to the laser-based is that you can get very fine resolution, very nice surface features, details. You can remove the powder from smaller holes and channels.

But the downside is that it's much slower. It's many times slower than an electron-beam-melting type of an approach, and you need more supports and anchors to secure the features of the part down to the build plate so the parts don't distort and warp as the parts are being built.

The plus side of electron beam melting is it's, like I say, much faster and you have far fewer supports and anchors. That means...

Heller: Less post-processing.

Wohlers: Not only less post-processing, but also less material used to support the parts, so it builds faster, you have less scrap.

Also the parts come out, for orthopedic implants, not entirely ready to go, but you can build what's called a trabecular surface, which allows for osseointegration. Bone likes titanium and [they'll] grow right into it. They produce these structures with this process, that permit the bone to better interface and adhere to the implant.

Steve Heller owns shares of 3D Systems and Arcam. The Motley Fool recommends and owns shares of 3D Systems. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.