Martz has a good answer. Give him the credit. To add some more details, however:
I'd say that particular type of drawing is a hand drawn conceptual sketch. The idea is to show the rough concepts of a product's design. Usually its form, along with surface decoration (colors, textures, etc.)
The style it is done in as a marker rendering. Specifically the large swashes of color.
The drawing itself, however, may use many different tools. Typically there's a rough pencil sketch to start, then followed by an ink pen or a fine pointed marker, then the broad blended color markers, and then the final highlights--such as the white reflected highlights--which are done with a paint pen (or paint, or white out).
If you went to art school prior to...oh...the mid '90's I suppose, marker rendering was likely a required course for anyone going into the design programs. I don't know if that's still the case anymore.
This type of drawing was common in the industrial design world--which Ive came from.
For whatever particular reason, other design disciplines have traditionally had slightly different styles. Architects did a lot of watercolor. Graphic Designers did a lot with colored pencils (now that I'm saying this, I'm beginning to wonder why that was, but I digress...)
Anyhow, these days--regardless of one's design discipline--most stuff is done on computers. For better and worse. The worse part is that a lot of the warmth and spontaneity was sucked out of drawings. However, within the past decade, lots of computer software has brought the analog back and I think the Paper App is a great example of that. It's a digital product that let's you use the traditional tools to get that nice hand made look. Which certainly resonates with clients in a much different way. (I'd note that Autocad has been doing a lot with this as well...many of their desktop architectural software products and mobile sketching apps now emphasize the analog style).