Touchscreen Display:
Samsung’s Galaxy S2 boasts a 4.3 inch Super AMOLED display capable of an 800x480 resolution. That is enough for watching some HD content. Unlike an LCD screen, Samsung’s Super AMOLED technology shows minimal discoloration when tilted at different angles.Apple’s current iPhone 4 screen is 3.5 inch, but that may change as the iPhone 5 is expected to see an edge to edge 4 inch screen utilizing retina display technology. Reuters

One of the most talked-about smartphones right now apart from the iPhone 5 is Samsung's Galaxy S2.

Galaxy S2 has sold a whopping three million units outside the U.S., beating the iPhone 4 and upstaging the rumored iPhone 5. The phone is already being hailed as the best smartphone going, and is the most successful unit of its kind in the UK market.

Samsung is expected to launch four versions of the smartphone in the U.S. in July, and is expected to provide stiff competiton to the iPhone 5, which is expected in September.

In the U.S., Samsung Galaxy S2 will release as Within on Sprint, Attain on AT&T and Function on Verizon. And latest reports say T-Mobile is expecting the Hercules version.

On the other hand, Apple's iPhone 5 remains the most anticipated smartphone in the U.S. market. And Apple's projection of selling 25 million iPhones by the end of 2011 lends credence to the expectation that the release is just around the corner.

A new ChangeWave survey says nearly half of its respondents (48 percent) who are planning on buying a smartphone in the next 90 days say they'll get an iPhone -- up 1 percent since its previous survey in March and the highest level of demand in the smartphone industry.

The specs of the next iPhone have been speculated for months. However, it is strongly rumored that iPhone 5 will run on Apple's latest mobile operating system iOS 5.

Meanwhile, Apple has a complete ecosystem that gives it a distinct edge over Galaxy S2. Apple's App Store, which has 425,000 apps, has recently topped the 15 billion download mark.

Although smartphones running Google Inc.'s Android OS continue to gain share of total smartphone units sold, when it comes to profits, Apple remains the undisputed king, raking in roughly 50 percent of the entire handset industry's net earnings during the first quarter of 2011, Canaccord Genuity said in a note to clients.

As a result, technology enthusiasts are gearing up for an intense of the two smartphones.

Below are the expected features of Apple's iPhone 5 in comparison with the Samsung Galaxy S2:

Display:

Samsung Galaxy S 2 features a super-sized 4.3-inch Super AMOLED display with 800x480 screen resolution. Galaxy S2's Super AMOLED display is superior to an LCD screen as it shows minimal signs of discoloration when tilted unlike LCD screens.

iPhone 4 had a screen size of 3.5-inch with multi-touch display which will now see a major change with the upcoming iPhone 5. The new Apple iPhone 5 is expected to have a bigger edge-to-edge 3.7 to 4-inch curved glass screen.

Processor:

The Galaxy S 2 is powered by a Dual-core 1.2GHz ARM Cortex-A9 proccessor, Mali-400MP GPU, Exynos chipset.

On the other hand, there is near unanimity in gadget circles that Apple will bring its A5 chip in to the iPhone 5. The A5 processor is the same which Apple rolled out to power its iPad 2. Apple may boost the speed of its A5 chip in the range of 1.2 or 1.5 GHz for iPhone 5.

Operating System:

Samsung Galaxy S2 runs on Android 2.3, while iPhone 5 will have Apple's upgraded mobile operating system iOS 5 along with iCloud service.

The new iOS 5 is expected to come with 200 new features that will include Improved Notifications System, News Stand and iMessage.

Camera:

Samsung Galaxy S 2 comes equipped with an 8MP rear-facing with LED flash and a 2MP front-facing camera, offering 1080p video playback.

Galaxy S2's camera is considered to be of good quality with the only snag being that photos with high contrast between dark and well-lit areas result in deep shadows or blown out highlights reports Engadget.

Apple's iPhone 5 is also expected to sport an 8 megapixel camera with 1080p video playback and panoramic photo capture. It has been reported that OmniVision/Sony would supply 8 MP camera sensors. iPhone 4 has a 5 megapixel camera with LED flash.

Connectivity:

Samsung Galaxy S2 offers download speeds of up to 21 Mbps on HSDPA and upload speeds of up to 5.76 Mbps on HSUPA.

On the other hand, iPhone 5 is expected to have HSDPA between 14 Mbps and 21 Mbps.

Memory:

Samsung Galaxy S2 comes in 16/32 GB internal memory configuration with MicroSD up to 32GB. The phone has a 1GB RAM.

It is expected the iPhone 5 will have 16/32/64 GB internal storage. iPhone 4 has fixed 16/32 GB internal storage and doesn't have external storage, but that doesn't matter as 32 GB at the maximum is generally enough for the users.

Battery Backup

Samsung Galaxy S2 offers talk time of up to 18 hours in 2G and about 9 hours in 3G. Meanwhile, standby time comes around 710 hours in 2G and 610 hours in 3G.

We can expect a great battery life in iPhone 5 as Apple has a record of improving battery life with its every coming product. The iPhone 4 has 40 percent more talk time than the iPhone 3GS.

There are expectations that the upcoming iPhone should improve on its battery metrics to handle its sophisticated features.

Currently, iPhone 4 offers talk-time of up to 7 hours on 3G; up to 14 hours on 2G (GSM model only) and standby time of up to 300 hours. On internet usage, the device offers up to 6 hours on 3G and up to 10 hours on Wi-Fi.

Pricing:

Apple's iPhone 5 is expected to hit the markets in September and has been rumored to be priced at $600.

The Galaxy S 2 is expected to be priced at $599 to $699 for an unlocked 16GB version, while the locked version to be sold on contract from U.S. wireless carriers is expected to be in the $250 to $300+ price range.

For a handset with such a broad range of standout features and specs, the Galaxy S2 is remarkably easy to summarize. It's the best Android smartphone yet, but more importantly, it might well be the best smartphone, Engadget said in its review.

Nevertheless, Apple's iPhone features are extensively varied from Galaxy S2, which means loyal Apple fan base remains the same. And for Apple, there is no reason to fear a potential loss with respect to buyers.

Apple certainly knows how to surprise and already has a few things in place like iCloud which can steal the thunder from Android devices. It's the first time that Apple is not leading the pack but has to play catch-up with Android smartphones.