Apple has unveiled two new handsets: the top-end iPhone 5S and acheaper iPhone 5C at an event in California.

The 5S introduces a fingerprint sensor built into the phone's main button to identify the user. The 5C comes with a plastic back in a choice of colours.

It marks a change of strategy for Apple which had not launched two distinct types of handset at the same time before.

The iPhone is the firm's most important product in terms of earnings power.

The new fingerprint system can be used to unlock the 5S and provide authentication for purchases from Apple's online marketplace.

Apple is covering the fingerprint sensor in sapphire crystal to prevent scratches impairing its performance

One analyst suggested the feature would help the handset stand out against its Android rivals.

"Touch ID is actually quite an elegant solution to an ever more significant problem: namely, the theft of mobile devices and, perhaps even more critically, the information stored on those devices," said Windsor Holden from the tech consultancy Juniper Research.

"Many people haven't yet bothered to implement any kind of security solution on their handsets and for those who have, securing handsets with Pin authorisations can be quite a time-consuming process."

However, Apple is not the first phone company to offer such a fingerprint reader.

Motorola added the facility to its Atrix handset in 2011, but many owners had problems using it. The feature is not included in the Google-owned business' latest models.

The new handsets are compatible with the radio frequencies used by O2 and Vodafone's new 4G services in the UK. The only 4G network the old iPhone 5 could use was EE's.

'Not cheap'

The 5S' Sim-free price ranges from £549 for a 16 gigabyte version to £709 for a 64GB model.

The basic 5C model, with 16 gigabytes of storage, has been priced Sim-free at £469. That is more than UK retailers had been charging for the 4S with the same amount of memory.

"The 5C is far from being 'cheap' as the iPhone 4S [which now costs £349] continues in that role," remarked Ben Wood from tech advisors CCS Insight.

There had been speculation that the 4S was going to be phased out.

The new iPhones go on sale in the US, UK, China, Australia and Canada among other countries on 20 September. It marks the first time China has been included in the initial wave of sales.

For all the usual superlatives about the amazing capabilities of its new phones, today's Apple event was more about new markets than new technology.

True, the iPhone 5S does have one major innovation in the fingerprint sensor, a security feature which may help make consumers more confident in banking and shopping online.

Under the bonnet, it may also prove to be the fastest smartphone on the market - for a few months until the game of leapfrog continues. But in appearance - unless you go for the gold version - you would be hard put to differentiate it from the previous model.

But the big and risky move is the arrival of the cheaper, more plasticky and colourful iPhone 5C. Apple's has been so successful in burnishing the iPhone's luxury brand and thereby keeping its margins sky-high that it may well qualify as the most profitable single product ever made.

If the kind of people who have always traded up to the top-of-the-range new iPhone opt instead for the cheaper version, that will eat into Apple's profits. But Tim Cook and his colleagues are betting that this product will instead widen the appeal of the phone.

In particular, it is China where the prize is huge. Chinese consumers seem to admire the iPhone, but what they buy is Android phones in huge numbers, with Samsung and the home-grown Xiaomi both very popular.

Now Apple, which has seen its market share dwindle over the last year, will hope that it can make a bigger dent in what is the world's biggest mobile phone market.

What it hasn't done is anything much to surprise and excite either investors or the wider world. Under Tim Cook, Apple is still waiting for a "wow" moment to give it new momentum.

Source: BBC News online.