It's that day of the year, writes Ash Casson.

The second most anticipated day of the year for Apple fans around the world; iPhone unveiling day (the first being a couple of weeks away when they can get their hands on it).

Every year, in the six months prior to the September unveiling, the rumour mills begin to get exponentially wilder and wilder. Ideas, concepts, pictures and videos begin to spread across the internet like wildfire. Some arguably believable, some just plain out-there. From eyeball-scanners to laser-keyboards, the ideas get a bit out of hand. And then it hits. The media gathers at Apple's Cupertino HQ around 10am their time, the rumours are put to bed and the real thing is unleashed upon the tech world.

Some hearts are filled with emotion, some are broken, some couldn't care less. Whether you're an iPhone fan or not, news of the latest iteration hits you sooner rather than later. The announcement day, and the days that follow see the iPhone dominate not just the smartphone news, but the tech news as a whole.

So now the cat is out of the bag, let's take a look at what we can expect over the coming weeks (and months).

Firstly, there are once again two versions being released; the '6' and '6 Plus'. This time though, rather than the primary difference being the materials from which they're made, it's all about size.

Over the past few years, while most smartphones have grown increasingly bigger, iPhone has remained mostlythe same size, minus one small increase a couple of years back. This time round, the iPhone's display is increasing from 4 inches to 4.7 inches and a somewhat gargantuan 5.5 inches in the iPhone 6 and 6 Plus respectively.

Both phones have moved away from the square edge design and to a somewhat iPod Touch-esque curved design, but as always, thinner than their predecessors. They both have an increased resolution thanks to "Retina HD" and screens that curve at the edge to create a "more seamless experience when swiping".

Is it all about size?

As with most popular ranges of smartphones, going from one generation to the next rarely yields thatmuch change. This leap probably sees the biggest jump since the redesign from curved to square shape going from the 3GS to 4. Most new generations of iPhone have brought along with them a new version of its iOS operating system, and the 6 and 6 Plus are no exceptions.

The latest version - iOS 8 - brings with it a slight design refresh and small - though Apple would probably call it huge - array of new features.

Their 'iMessages' app sporting several of these with the 'new' ability to send voice notes, location information and other 'useful' information. As with all other generations, Apple have done some work under the hood and not just to the design. They've kitted the two new handsets with their improved A8 processor - "offering 25% more CPU power and a 50% GPU boost while using no more battery power than previous" (or to put it into less techie terms, it's faster and looks nicer).

The iSight camera is "hugely improved" according to Apple, though many are a little disappointed it still sports the same number of pixels - 8 million - as the iPhone 4, some four generations previous. What the larger 6 Plus does give you, however, is something called Optical Image Stabilization (OIS) which allows the camera to move slightly within its shell to compensate for the shaking of the user's hand - something that's been around for a while in smartphone cameras but is a first for Apple. Both handsets have a True Tone dual LED flash on the back to capture more realistic colour and light in low-light conditions.

It isn't just size that differentiates between the two new handsets. The iPhone 6 Plus carries a few other tricks up its sleeve that will attempt to justify the extra you'll pay, should you choose it over its little brother; the aforementioned OIS on the camera; a higher resolution screen (401 pixels per inch over the 6's 326); and better battery life.

Both models come in slightly difference memory capacities than previous models, this time in 16GB, 64GB and 128GB. Apple have left out the 32GB variant in favour of the new maximum of 128GB.

In short, the latest generation does take some jumps forward, but some features don't make the evolutionary jump some were hoping for, particularly in the camera department. The design is "radically" different, at least for Apple, but day-to-day usage isn't going to change much from your "old" iPhone 5S (or 5, or 4S, or 4…).

It's going to look stunning, a true piece of technological and engineering artwork, but it's fundamentally the same phone that's already out there. It's just bigger, thinner and faster (as with all new generations of most smartphones). This isn't a bad thing. If Apple changed toomuch, I imagine more people would be annoyed than are currently claiming not enough has changed.

There is absolutely no doubt in my mind this will - yet again - be the best selling iPhone in history. Warehouses will (apparently) run out, production lines (apparently) won't be able to keep up with demand and waiting lists will form. Apple don't just sell products, they sell ideas, dreams and emotions all bundled together. Apple fans will "need" it and admirers will want it. Along with the keynote speech given for the new phones, absolutely immaculate promotional videos appeared too, just in case you didn't realise how much you needed one.

Pre-orders for both handsets start September 12 and the handset is expected to be available September 19 (expect people camping outside Apple stores from September 18).

Alongside these new iPhones starred Apple's first venture into the world of smartwatches. What was expected to be called the 'iWatch' emerged as the simply-named Apple Watch. This device, however, I feel deserves a piece all to itself, so watch this space.