Samsung has unveiled its highly anticipated Galaxy Fold device, which unfolds "like a book" from a smartphone into a tablet.

According to Samsung, the Galaxy Fold, which will go on sale in two months, sits in its its own technology category – wavering between the two different devices.

Unfolded, the device has a 7.3-inch size and functions as a tablet, however when folded in half it can be used as a regular touch-screen smartphone with a 4.6-inch screen.

"It delivers a new kind of mobile experience allowing users to do things they couldn't do with an ordinary smartphone," said Samsung.

"Users now have the best of both worlds; a compact device that unfolds to reveal Samsung's largest-ever smartphone display."

Instead of bending like its more rounded concept design appeared to, the new device folds – described by Samsung as "a more intuitive motion, and a more difficult innovation to deliver."

The design features a hinging mechanism with multiple interlocking gears, concealed within a hidden enclosure to create a "seamless" look. This system allows the device to open "like a book" and close flat with a "satisfying click".

The phone's screen is made from a composite polymer rather than the traditional glass screen. According to Samsung, it is the "world's first" Infinity Flex Display with an active-matrix organic light-emitting diode (AMOLED) screen that allows for a faster, higher definition display.

The electronics brand revealed its design of the Galaxy Fold today at a series of its Unpacked events held across London and New York.

After ten years in the making, the new foldable device will go on sale in just a few months time – released in the U.S on 26 April with a price tag of $1,980, and then on 3 May in Europe.

"Today, Samsung is writing the next chapter in mobile innovation history by changing what's possible in a smartphone," said head of Samsung Electronics DJ Koh at the unveiling.

"Galaxy Fold introduces a completely new category that unlocks new capabilities never seen before with our Infinity Flex Display," he added.

"We created Galaxy Fold for those that want to experience what a premium foldable device can do, beyond the limitations of a traditional smartphone."

Suited to those who like to multitask, users can open up to three active apps simultaneously on the main display so that they can browse the internet, work, text or watch videos at the same time.

A new software system called app continuity allows users to pick up where they left off when switching between the open and folded displays. This ability to multitask is also supported by a specially engineered dual battery system.

The phone also has six camera lenses – three in the back, two on the inside and one on the cover – to ensure that users are ready to capture an image at any moment.

The Galaxy Fold will be available in a variety of colours including Space Silver, Cosmos Black, Martian Green and Astro Blue, with Samsung's logo engraved on the hinge of each device.

Samsung managed to unveil the foldable device ahead of its rivals, giving it the edge over companies such as Huawei Technologies, which announced plans to launch a 5G smartphone with a foldable screen in mid-2019, and Chinese start-up Royole, which unveiled a foldable Android phone back in November 2018.