Apple has announced the addition of not one, but two devices to its iPhone line-up. The iPhone 5S heads to the top of the iPhone range and becomes the new premium model, while the iPhone 5C replaces the iPhone 5 and becomes the budget option. Yes, that's right, no more iPhone 5.

Read on to find out what the differences are between the two new models, and what you can expect from these two devices in terms of specs.

Display: Exactly the same

You might choose the cheaper model, but you won't lose out when it comes to the display. Both sport a 4-inch Retina display featuring an 1136 x 640 resolution and pixel density of 326ppi. Just like the iPhone 5, they both deliver an 800:1 contrast ratio, so at least you're not loosing out by taking the model lower down the ladder.

iPhone 5C is plastic, iPhone 5S is aluminium

The build of the iPhone 5S and iPhone 5C is probably the most obvious difference. One is aluminium and the other is polycarbonate. You certainly won't be getting the two mixed up anytime soon.

READ: Apple iPhone 5C pictures and hands on

READ: Apple iPhone 5S pictures and fingers on

The iPhone 5C comes in with slightly larger dimensions than the iPhone 5S, measuring 124.4mm in height, 59.2mm in width and 8.97mm in depth. In comparison, the iPhone 5S is 123.8 x 58.6 x 7.6mm. It's really only a matter of millimeters.

The iPhone 5C also weighs slightly more, knocking the scales up to 132g, while the iPhone 5S weighs 112g, the same as its predecessor the iPhone 5.

iPhone 5C is colourful, iPhone 5S is sensored 

When it comes to colour, the iPhone 5C is laughing compared to the iPhone 5S. With only three variants for the iPhone 5S, which is still more than before, the iPhone 5C trumps it with five.

The iPhone 5S comes in silver, space grey and gold, while the iPhone 5C comes in white, pink, yellow, blue and green. That's right, no black.

However the iPhone 5S has its own trump card after Apple added a fingerprint reader to its design. Touch ID has been built into the home button with a stainless steel detection ring around it to detect that your finger is on the button.

READ: Apple iPhone 5S: Everything you need to know

The rectangle mark has been removed and the sensor is 170 microns thin, features a 500ppi resolution and has 360-degree readability.

You'll still find the rectangle mark on the iPhone 5C though, so if the colours didn't give it away, you'll certainly be able to tell you don't have the iPhone 5S when your finger alone doesn't have the power to unlock your device.

The iPhone 5S has a better camera

As you would expect, the iPhone 5S comes out on top with the camera. It had to somewhere, otherwise what would be the point in a premium model?

Both handsets come with an 8-megapixel rear camera with a five element lens, just like the iPhone 5. The iPhone 5S comes with a third of a stop brighter aperture, f/2.2 than the iPhone 5C, f/2.4, in order to let more light in.

Where they differ is the flash. The iPhone 5C comes with an LED flash, the same as the iPhone 5, whereas the iPhone 5S comes with a dual-LED True Tone flash.

The True Tone flash is designed to solve the problem of clashing colour temperatures by using one of two filtered outputs. Ideal for skin tones. Apple has also introduced a Burst mode on the iPhone 5S, which allows you to take up to 10fps if you hold the shutter button down.

READ: iPhone 5S camera: new sensor and lens, can Apple keep Nokia at bay?

They both have a Hybrid IR filter, autofocus, face detection and panorama modes. Plus, they are both capable of 1080p HD video recording, along with 720p HD video recording from the 1.2-megapixel front camera.

You will get improved video stabilisation and Slo-mo 720p 120fps video with the iPhone 5S however.

The iPhone 5S is faster

There aren't a great deal of differences between these two devices, but the processor is one of them. The iPhone 5S comes with the new 64-bit A7 processor, while the iPhone 5C sticks with the A6 found in the iPhone 5.

It will mean the iPhone 5S is 2x faster in terms of CPU and graphics compared to the iPhone 5C. The iPhone 5S also comes with an M7 motion coprocessor, which is designed to help monitor motion data continuously with an accelerometer, gyroscope and compass support. Basically it will improve your experience with fitness apps, it seems.

READ: Nike+ Move will be first motion app for iPhone 5S, taking advantage of M7 processor

Battery-wise, you'll be getting a 25-hour boost in standby time in both devices compared to the iPhone 5, but other than that, no change between the devices or the iPhone 5. The iPhone 5C and the iPhone 5S come with up to 250 hours standby, 8 hours with 3G browsing, 10 hours of video playback and 40 hours of audio playback.

In terms of connectivity, these two phones show absolutely no difference. They both support Bluetooth 4.0, Wi-Fi 802.11a/b/g/n and 802.11n on 2.4GHz and 5GHz, as well as wide LTE coverage.

Apple has said the iPhone 5S will support all forms of 4G LTE, compared to the iPhone 5, which only supported EE.

The iPhone 5S is more expensive, obviously

Of course, if you choose to go for the iPhone 5S and a few of its better features, you will pay the price. SIM-free, the iPhone 5S starts from £549 for the 16GB, creeping up to £629 for the 32GB and £709 for the 64GB.

READ: Apple iPhone 5S: Release date and where can I get it?

In comparison, the iPhone 5C will cost you £470 for the 16GB and £550 for the 32GB, both SIM-free. There is no 64GB model available.

READ: Apple iPhone 5C: Release date and where can I get it?

Both models will be available in stores across the UK, US, Canada, France, Germany, Japan, Australia, China, and Singapore from 20 September, with the iPhone 5C available to pre-order from 13 September.