Last week, technology research firm Gartner updated its forecast for computer, tablet and mobile phone sales through 2019. For 2015, the total device shipments are expected to reach nearly 2.5 billion units with mobile phones providing 78% of total devices shipped. Overall, the estimated number of shipments this year is expected to grow nearly 2.8% from last year's figure of 2.42 billion.

Looking beyond the headline number, and focusing on the type of device, points toward a bifurcating market with growth in the high-end markets and sales decreases in the price-sensitive, commoditized traditional PC market. For perspective, here are Gartner's figures:

Device 2014 2015 (est) Growth Traditional PCs 277,118 252,881 (8.7%) Ultramobile (Premium PCs) 36,699 53,452 45.6% Ultramobiles (Tablets & Clamshells) 227,080 236,778 4.3% Mobile Phones 1,878,968 1,943,952 3.5% Total Devices 2,419,864 2,487,062 2.8%

One of these things is not like the others...actually, two aren't

When it comes to personal computers, the differences between traditional PC growth and ultramobile PC growth are the largest departures from overall growth. Gartner points toward a currency headwinds for European enterprise buyers as the Euro continues to sink against the dollar. Traditional PC makers Hewlett-Packard and Dell will continue to face headwinds from enterprise PC buyers, along with semifinished good providers Intel and AMD that provide the chips and processors for these computers. Gartner predicts these firms will raise prices to offset currency headwinds -- in order to keep margins -- but this will result in fewer units sold.

Meanwhile, the high-end ultramobile PC market will continue to grow, according to Gartner, as the nonenterprise personal computer market is less price elastic amid more product differentiation. In addition, many companies that are spending on computers are opting for bring-your-own-device (BYOD) policies and/or giving employees more input on device selection, potentially providing a lift to ultramobile PCs.

Good news for Apple?

Gartner specifically mentions Apple's (NASDAQ:AAPL) MacBook Air as an example of a ultramobile PC, and Apple's had a great run with its Mac line over the last two years. Here's a visual representation of Apple's unit growth on a year-over-year basis:

As you can see, on a unit basis, Apple's done really well in its Mac line, attaining double-digit growth on a year-over-year basis in three of the last four quarters. Recently, the company added the new 12-inch MacBook line to its Mac line of laptops -- joining its MacBook Air and MacBook Pro and giving shoppers more choice.

Don't forget the iPhone

But it doesn't just end there, Gartner's report gives great news for Apple's core business, its iPhone line, by forecasting iPhones will continue to steal market share away from Google's Android operating system. Per the report, "Android vendors at the high end are finding it hard to differentiate and add value beyond the technology and features," said research director Roberta Cozza. In addition, Cozza pointed toward Apple's ecosystem and new larger form factor as reasons for Apple's continued market share growth.

And that's important: Apple will need to steal market share away from Android vendors if Gartner's estimates for smartphone growth through 2017 is correct. After a year-over-year gain in total smartphone shipments of 3.5% this year, Gartner estimates for worldwide smartphone shipments to increase 3.8% in 2016 before dropping to 1.9% in 2017. For Apple to continue its amazing iPhone growth, the company will have to steal market share from Android.

Overall, Gartner's report is good news for Apple fans as the research firm points toward a strengthening market in its Mac line and continued market share gains in its core smartphone market.