Amazon announced the first Kindle in 2007 and since then we have seen seven generations go by. The eighth more recently became available in the form of the Kindle Oasis and it heads the current line-up of the Kindle, Kindle Paperwhite and Kindle Voyage.

All four Kindles vary in price points and features, making the decision of which to buy a little more complicated than just adding an eBook reader to your Amazon basket and checking out.

We have compared the Kindle Paperwhite that launched in 2015, the Kindle Voyage that arrived in 2014 and the latest Kindle Oasis to help you work out what the differences are between them and how the three high-end Kindles compare.

All three of the Kindles being compared here offer a 6-inch E Ink Carta display with touchscreen technology. There is a lot more to it than just size though.

One of the most important things on an ebook reader is resolution. When Amazon launched the 2015 model of the Paperwhite, it doubled the resolution, putting it on par with the Kindle Voyage with both offering a pixel density of 300ppi. The Kindle Oasis also offers a 300ppi, meaning all three offer the same resolution.

In terms of contrast, the Kindle Voyage has a higher contrast than the Paperwhite, and although the Oasis contrast hasn't been detailed, we suspect it will be the same as the Voyage, if not higher.

Another thing to note regarding displays is all three Kindles have touchscreens as well as built-in front illumination, with the Voyage also offering an adaptive front light. This adaptive front light will dim and brighten depending on where you are, which should make going inside or outside effortless as the Kindle adapts brightness to make reading as easy as possible. The new Kindle Oasis doesn't offer this feature.

The Oasis does have 60 per cent more LEDs in its built-in light however, as well as new diffractive patterns to help increase the lighting consistency and range of screen brightnesses. This is said to offer improved reading in all types of lighting so it could be that the adaptive front light feature isn't offered on the Oasis as doesn't need it thanks to other display improvements.

The Amazon Kindle Oasis is the slimmest and lightest Kindle available. It measures 143 x 122mm and it is 3.4mm at its thinnest and 8.5mm at its thickest. The Oasis Wi-Fi only model hits the scales at 131g without the accompanying cover and 238g with the cover, while the Wi-Fi and 3G model weighs 133g and 240g, respectively.

The Oasis is squarer than its siblings and the design is entirely different. The weight, or what weight there is, is all within the block on the right, which is where all the hardware now sits compared to being distributed across the entire device like the other Kindle models. This makes the Kindle Oasis very comfortable and easy to hold as it has been designed to move the centre of gravity to your palm for one-handed reading.

It comes with a leather battery cover that slots on the rear and sits inline with the raised block, offering a smooth rear when on, compared to the right bump when off. The cover is attached via magnets so it is easy to take off if you want to read without a cover. When on, it is designed to open like a book, waking the display up when it does and fitting closely around the bezel.

The Kindle Voyage has a glass screen that sits flush with the front of the device for clear reading. This is also "micro-etched" meaning it helps stop reflections, which in turn should make outdoor reading easier. It is also said to aid in helping the screen mimic real paper.

The Voyage Wi-Fi model is 180g, while the Wi-Fi and 3G model is 188g, making it quite a bit heavier than the Oasis without its cover. It measures 162 x 115 x 7.6mm.

The Kindle Paperwhite has a very similar design to the Voyage, with the only main difference being in the bezel and the rear design. The Wi-Fi model weighs 205g, while the Wi-Fi and 3G model weighs 217g, both of which are heavier than the Voyage and the Oasis. The Paperwhite is also larger and thicker, measuring 169 x 117 x 9.1mm.

One of the other big design differences between these Kindles is how you turn pages and given that the main purpose is reading, this is a pretty important feature to consider.

The Kindle Oasis offers physical page turn buttons on the right-hand side where you hold the device, as well as the option to use the touchscreen. This makes things lovely and simple as you can turn pages with your thumb nice and easily without having to move your hand if you don't want to. There is also a built-in accelerometer so the Oasis can detect which hand you are reading with and automatically rotate the page and page turn buttons accordingly.

The Kindle Voyage offers a feature called PagePress. This uses sensors in the bezel to allow the reader to turn a page by simply pressing a little harder. Again, no moving of the hands to turn a page but perhaps not quite as easy as pressing an actual button like the Oasis offers.

The Paperwhite relies on the touchscreen for a swipe to turn the pages. This is a little more fiddly than on the Oasis or Voyage as you will need to move your hand to either tap or swipe the display, but some might prefer this method.

The Amazon Kindle Oasis offers months on a single charge according to Amazon, thanks to a new dual-battery design. The Oasis leather cover will recharge the device as soon as it is connected and both can be charged at the same time. There is also a new hibernation mode that will minimise consumption when you aren't using your Kindle.

Both the Kindle Paperwhite and Voyage offer weeks on a single charge, which is still great, just not as great as months. These stats are based on 30-minutes of reading a day with Wi-Fi turned off and brightness set to 10. 

All three Kindles offer storage for "thousands of books" according to Amazon.

All three of the Kindles being compared here offer the same software, which includes a font called Bookerly.

The Kindle software has come along way since it first arrived, with users now benefiting from better character spacing, hyphenation, justification and more. Reading larger fonts is also a lot easier now too.

The Amazon Kindle Oasis usually starts at £270, the Kindle Voyage at £170 and the Kindle Paperwhite at £110.

It is worth remembering the Oasis comes with a leather cover included in that price, which is available in Merlot, Walnut and Black colour options, but the Oasis is of course still significantly pricier than the Voyage or Paperwhite.

The Amazon Kindle Oasis is the most expensive Kindle available, but there are a few reasons for that, it just depends on whether any of them are good enough reasons in your opinion to consider it over the Voyage or Paperwhite.

The Oasis offers a newer design which is not only slimmer and lighter than its Kindle competition, but it is also smarter looking and designed to be more ergonomic and comfortable when it comes to extended reading sessions.

The extra money also offers you months of battery life instead of weeks, as well as a new display and a leather cover. Whether that's enough to warrant the extra £100 from the Voyage or the extra £160 from the Paperwhite really depends on what you are looking for in your Kindle. What do you need to make your reading experience the best it can be?