Mobile phone reviews: Features explained

Mobile phone features

Smartphones can do so much more than simply make calls and send texts. But what are the most important features? And which can you do without? Read on to find out what to look for when shopping for your new phone.

Know what you're looking for? Read our smartphone reviews to find the models that impressed in our tough lab tests.

Click the links below to skip to the relevant information.

  • Memory - how much memory you need.
  • Hardware - a closer look at batteries and processors.
  • Software - smartphone operating systems and app stores.
  • Entertainment - cameras, web browsers, music players
  • Connectivity - the common ways of connecting your device, from Bluetooth to 4G.


A large, sharp screen makes all the difference when watching movies or surfing the web but the best displays can be expensive. And big screens can quickly drain your phone's battery.

Screen size

As people have begun to watch videos and surf the net on their smartphones, manufacturers have responded by producing phones with bigger and bigger screens. In fact the line between tablets and phones has blurred with the launch of models such as the Samsung Galaxy Note II with its 5.5-inch display (measured diagonally from corner to corner).

However these large displays come at a cost – models tend to be more expensive and can be hard to fit into your pocket. Illuminating such large areas is very power hungry so battery life can be short.


The resolution is the number of pixels on the screen (listed horizontally and vertically). 

Pixels per inch

Screens with more pixels per inch should produce more detailed images and text

On screens with high resolutions, each pixel is extremely small and so images are much sharper – when there are fewer pixels each one has to be much bigger and so pictures are less detailed. When buying a new phone look for a resolution of at least 480x800.


PPI (pixels per inch) is used to measure the number of pixels found within a square inch on a display. This takes into account both the resolution and screen size, helping to give a better idea of how sharp and clear a screen will be.

The first iPhone featured a 3.5-inch display with a 320x480 resolution, meaning that it offered 165ppi. The Retina display used on the iPhone 4S is the same size but has a resolution of 640x960 meaning that it offers exactly double the pixel density (330ppi).



It's tempting to store hundreds of photos, songs and videos on your phone. But if you've only got a small memory then this can quickly fill up and it may cause programs to stop working properly and your phone to run very slowly. If that happens you'll need to clear space or boost your capacity, either by using a card slot or online storage.

Internal memory

All mobile phones have a memory which allows you to save information. Cheaper models will usually only have a small memory, but this is usually sufficient for limited functions such as storing contact details and text messages.

However if you plan to store lots of music, photos and apps then you'll need a larger memory (as a guide, an 8GB memory will be able to store around 2000 songs).

Memory card slot

A card slot lets you boost the phones internal memory. And because you can remove the card it makes it easy to share  photos and music

Memory card slot

Not all phone’s have card slots (famously iPhones don’t) but they’re very useful as they let you boost your phone’s memory. MicroSD cards are pretty cheap, you can buy a 32GB one for around £25, but you should check what size your phone is compatible with before you buy.

Cloud storage

Some premium smartphones include free online storage (also called cloud storage) through services such as Dropbox. Not only does this boost the your available storage space but it means that your photos and videos won't be lost if your phone is broken or stolen. And because your files are stored online it's easy to share them with your friends and family.



To keep a smartphone running smoothly you'll need one with a long lasting battery and powerful processor - without these you'll find it very frustrating to use.


Because smartphones have large screens and can perform lots of power hungry tasks, their batteries often last for less than 24 hours. Some heavy phone users even carry spare batteries but many newer phones have sealed backs meaning you can’t swap in a new battery if it runs out of power.

Manufacturers have introduced larger and larger capacity batteries (the 3100mAh battery in the Samsung Galaxy Note II has twice the capacity of those found in most phones) but short battery life remains a common complaint. That’s why we don’t publish any mobile phone review without fully testing the battery life on calls and when surfing the web.

Apple A6 processor

The iPhone 5's A6 processor is twice as fast and has twice the graphics power of its predecessor


The phone's processor is effectively the phone's brain, telling it what to do and how to do it. Its performance is measured according to the number of tasks it can complete per second, known as a ‘cycle' - a 1GHz processor can process one billion cycles per second.

Typically a processor with a higher speed will perform better and will give a faster, smoother performance - though memory cache and RAM do also have an effect. When buying a new smartphone look for one with at least a 1GHz processor - anything slower and you're likely to see some lag, especially if you're running lots of programs at the same time.

In the last couple of years phone manufacturers have introduced dual core processors. Having two chips means the phone is better at multi-tasking as one can handle background tasks while another can work on your active task. The extra power also means faster interfaces and enables new functionality such HD video recording, plus because each core works less hard to accomplish a task, the phone should use less battery power.

We've now started to see phones that run on quad core processors. In theory quad-core chips promise even faster performance and better battery life but we're yet to be convinced that they're really necessary as currently there are few applications that can make use of this extra power - though that will change in the future.



Phones aren't like computers so you can't install a different operating system (OS) if you don't like the one that came preloaded. It's therefore crucial to decide what you want before you buy your new handset.

Operating system

A phone’s operating system is the software that makes things work. There are four main smartphone operating systems: Apple iOS, Google Android, Windows Phone and BlackBerry OS. Your choice will affect the way your phone looks and feels and what it can do.

App stores

Smartphones can download software applications or apps that add new features to the phone. Apps come in all shapes and sizes – there are game apps, news apps, food apps, business apps – many of which are free.

Each operating system has its own app store where you can browse what’s on offer, read user reviews and then download your chosen app.


All smartphones come with their own mapping service and GPS receiver. This can help you plot routes and many will even provide turn by turn voice navigation, just like you’d get from a dedicated sat nav.



Smartphones mean that you no longer need to carry round separate cameras, music players and laptops. However their performance can vary dramatically - read reviews of our Best Buy mobile phones to discover the models we recommend.


The typical mobile phone camera resolution is now over 3Mp (megapixels). This is still short of the standard mid-range digital cameras but resolutions are rising. Most mobiles can also record video though again the quality varies dramatically. Premium models, such as the iPhone 5, can even record in 1080p Full HD.

Video calling

A front facing camera enables you to makes video calls using services such as Skype or Apple's Facetime

Front facing camera

A secondary camera on the front of the phone lets you make video calls and is also useful for capturing self-portraits. The resolution and quality of the front-facing camera is usually inferior to the rear, main camera.

Multi media player

All but the cheapest phones include music players that allow you to play digitally stored music tracks (you’ll need a reasonable memory in order to save a decent size collection). Most phones will come with a supplied set of headphones but these are usually inferior to good quality separate sets. If you want to use your own pair, look for models with a 3.5mm socket so you can plug it in. For help choosing a new set read our latest headphone reviews.

Built-in video players let you watch pre-recorded movies or stream videos from the web. However to really enjoy these you’ll need a smartphone with a large, high resolution screen.

Web browser

Smartphones have their own web browsers that let you access the internet on the go. These work in the same way as the web browser on your computer, so you can set favourites and often have multiple pages open at the same time.

Surfing the net on your phone can be expensive (especially data hungry activities such as streaming videos) so if you plan to spend a lot of time online then it’s a good idea to choose a phone contract that includes a generous data allowance.



Even the most basic £10 phone lets you keep in touch with your friends. But spend a little more and you can make phone calls around the world, surf the net at superfast speeds and even stream movies around your house.

Frequency bands

Whether the phone is dual, tri or quad band, and hence which frequencies it works on. All phones sold in the UK will be at least dual-band and so can be used throughout Europe and many other countries (though you usually need to arrange this with your provider). A tri-band phone will work in most of North and South America although some areas may need a quad-band device.


If you plan to surf the web on your phone then you’ll want a device that offers at least 3G connectivity. Older or cheaper phones can go online via 2G (alternatively called GSM) but this can be painfully slow.

Most smartphones can now go online using an enhanced version of 3G called HSDPA. This o offers speeds of up to 14.4Mb/s - though networks tend to offer 3.6Mbps, which can download a song in 8.3 seconds


4G superfast web access is currently only available thtough EE, though other networks plan to launch rival services in 2013


4G is a new mobile phone technology that offers download speeds that are up to five times faster than 3G. Currently 4G is only available through special deals on the EE network but other networks will launch their own versions of the service in mid-2013.


This enables compatible devices to connect wirelessly to the internet either through your home network or via a Wi-Fi hotspot. This is usually much faster than connecting over a mobile network and won’t use up any data allowance you may have on your mobile contract.


Bluetooth is a way of wirelessly connecting your phones to other Bluetooth-compatible devices. It uses a short-range (1-10 metre) radio frequency, so the devices don't have to be in line of sight of each other and can even be in other rooms. Bluetooth is mainly used for hands-free devices such as Bluetooth headsets and hands-free kits, as well as transferring files from a phone to a PC or vice versa.


DLNA (Digital Living Network Alliance) enables you to share music, photo, and video files across a wireless connection. So for example, you could connect your smartphone to your home Wi-Fi network, and stream movies stored on the phone to your big screen TV.


NFC lets you wirelessly transmit data over very short distances. It’s a similar system to Bluetooth, though NFC is much faster. Some smartphones come with NFC smart tags that can be used to change the phone's set up. For example you could swipe the tag in your car to switch on Bluetooth, enable GPS and launch the satnav app - much quicker and easier than having to manually change all the settings.

But its NFC’s potential for making contactless payments that is causing most excitement and we’ve already seen the first phones that you can ‘swipe’ (like an Oyster card on the London Underground) to pay for items.

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