Bezel-less device

A bezel-less device is one with minimal bezels typically housing a display of an 18:9 or taller aspect ratio.

What is a Bezel-less phone?

A bezel-less device is one with minimal bezels. Bezel-less designs and 18:9 or taller displays have been a characteristic trend of 2017. Bezel-less displays are advertised by many different names. Bezel-less designs have some disadvantages:
Removal or Relocation of components
More fragile devices
Increased accidental inputs
Thicker devices

Bezel-less devices have various setups:
Reduced top and bottom bezels
Only bottom bezel
Display Notch
Secondary Display

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A bezel-less phone or a bezel-less device is one with no or small bezels. A bezel in a smartphone, tablet, laptop, TV or watch is the part of the front side not having a screen, that is, the non-screen part which surrounds the screen.

In the past, bezels on computer monitors and smartphone contained circuitry but later the bezels were there only for structural strength. With the beginning of 2017, bezel-less phones started gaining popularity and became a new trend and eventually bezel-less phones for all price ranges have been released. With slimmer top and bottom bezels the height of the screen in smartphones has been increased thus bezel-less phones commonly come with an 18:9(2:1) aspect ratio rather than the traditional 16:9.

What are the synonyms of bezel-less display?

OEMs have advertised their bezel-less devices using many different names such as infinity display(popularized by Samsung), full-vision display(popularized by LG), edge to edge display, edge-less display(popularized by Sharp), nano-edge display(popularized by Asus), full optic display(popularized by Oneplus), thin-bezel display etc.

Are there any disadvantages of going bezel-less?

The Apple iPhone X omits the fingerprint sensor

Yes, though bezel-less displays look really cool but they create several drawbacks for devices.

Removal or Relocation of components on the bezels

Several components like a home button cum fingerprint sensor, front camera, notification LED and several other sensors are traditionally placed on the top and bottom bezels. With the onset of bezel-less displays, several such components are either scrapped off completely or relocated and placed in other places which might cause inconvenience.

The Xiaomi Mi Mix replaces the proximity sensor and earpiece with ultrasound and piezoelectric ceramic respectively

More fragile devices

Due to more screen on the front side and curved screens, devices become fragile and more susceptible to cracks or shatters during the occasional accidental drops.

Increased accidental inputs

Lesser bezels sometimes cause accidental touch inputs in devices, these are a pain in the ass.

Thicker devices

A lot of devices especially laptops and tablets contain circuitry or internal components underneath the bezels. So if these bezels are to be removed, then the circuitry and components need to be placed under the display, these make the device thick.

What are the different bezel-less setups?

Samsung Galaxy note 8 features minimal bezels on top & bottom with a curved display.

Devices without side bezels or curved bezels at the sides(And fat bezels on the top and bottom) were earlier marketed as bezel-less. But with newer devices with lesser bezels. Most people don't consider them bezel-less any more.

Reduced top and bottom bezels

The LG G6 features minimal bezels on the top & bottom.

Most bezel-less phones omit the side bezels and contain minimal top and bottom bezels which are just big enough to accommodate the necessary sensors and the front camera but usually don't have a front facing fingerprint sensor. Devices having such a setup include the LG G6, Google Pixel 2XL and the LG V30. The Samsung Galaxy S8 and the Samsung Galaxy Note 8 also accommodate this setup but also have curved screens along with them.

Only bottom bezel

The HiSense Vidaa Mirror has a futuristic bezel-less design

In this setup, all bezels except the bottom one are removed, the front camera and sometimes the fingerprint sensor is placed on the bottom. the proximity sensor is either placed on the bottom or replaced by ultrasound. Devices with this setup don't usually have a conventional earpiece and use technologies like direct wave recievers(which can generate sound by vibrating the screen) or piezoelectric ceramic(which can generate sound from the metal frame). Phones having such a setup include the Xiaomi Mi Mix 2, Elephone S8 and the Panasonic Eluga C.

The Dell XPS 15 houses and infinity display

This setup is the only one used by laptops and tablets with bezel-less displays. Examples include the Dell Inspiron 7000, Dell XPS 15, Asus Vivobook S15 and the HiSense Vidaa Mirror.

Display Notch

The Essential PH-1 has a small display notch

Some device manufacturers have gone ahead of just reducing bezels and have created devices with no bezels but a protruding notch which accommodates the camera and sensors. Not all people are in favor of this setup as it might lead to inconvenience while looking at photos and apps might need to adapt their code to suit the notch. Yet it has been used in devices such as the iPhone X and the Essential PH-1.

Secondary Display

The LG V20 has a secondary display beside the front camera

Some devices have attempted to avoid a display notch by using a secondary screen adjacent to the notch. Secondary screens can show app shortcuts, information regarding the current app or other information like weather. This design was prevalent in the LG V series but has not been used in their latest flagship(the LG V30). The LG V20 has this setup.

The trend of bezel-less displays is likely to prevail and appear in most new devices and by it's popularity it seems that it is here to stay. If not forever, at least for a few more years.