Verizon Wireless began selling the much-awaited Samsung Galaxy Nexus for $299.99 on its network from Thursday, triggering an interesting competition within the Samsung devices.

Galaxy Nexus, which is considered as a prime rival to Apple's iPhone 4S, would also be a stiff competitor to Samsung's best-selling smartphone, Galaxy S2, which has been sold over 10 million units since its February debut.

On the carrier front, Galaxy Nexus would be Verizon's answer to all the other three leading carriers - AT&T, Sprint and T-Mobile - which carry Samsung Galaxy S2.

Samsung Galaxy S2, which runs on Android 2.3 Gingerbread OS, comes in three variants - on AT&T, T-Mobile and Sprint, whose version is called Samsung Galaxy S2 Epic 4G Touch

Galaxy Nexus, which features Google's Ice Cream Sandwich, was also known as Samsung Google Nexus Prime, Samsung Google Galaxy Nexus I9250, Samsung Google Nexus 3 and Samsung Google Nexus 4G.

Ice Cream Sandwich is a combination of Gingerbread and Honeycomb in one unit that include widgets in a new tab, a customizable launcher, Gmail with offline search with a two-line preview and new action bar at the bottom. Ice Cream Sandwich also has better voice integration, improved copy and paste and a new tabbed Web browser that allows up to 16 tabs.

Galaxy Nexus comes with dual-core 1.2GHz Cortex-A9 CPU, TI OMAP 4460 chipset, 4.65-inch high-definition Super AMOLED display, 1 GB of RAM, 16 or 32 GB of internal memory, NFC, 4G LTE support, 5-megapixel rear-facing camera with 1080p video capture and 1.3-megapixel front-facing camera for video calls. On the flip side, the phone would not support Google Wallet.

On the other hand, Samsung Galaxy S2 also doesn't lag on the specifications front. Both the T-Mobile and Sprint versions of Galaxy S2 have 4.52-inch display screens whereas the AT&T version retains the 4.3-inch screen of the versions sold worldwide.

The Galaxy S2 features an 8-megapixel camera with flash and can record HD video in 1080p. The phone also has a front-facing 2-megapixel camera for video chat.

As Galaxy S2 is also expected to get an Ice Cream Sandwich upgrade in early 2012, customers would be little skeptical over which smartphone to buy this holiday season.

Let's take a look at how these two devices fare against each other that may help in purchasing decision:

Display: Galaxy Nexus sports a 4.65-inch high-definition Super AMOLED display that may give a resolution of 1280 x 720 pixels with about 316 ppi pixel density. Galaxy S2 comes with a 4.3-inch WVGA SUPER AMOLED Plus display with resolution of 800 x 480 pixels at 217 ppi.

Size: Galaxy Nexus will come in 135.5 x 67.94 x 8.9 mm dimension and weighs 135 grams while Galaxy S2 is comparatively thin weighing 116 grams and has a dimension of 125.3 x 66.1 x 8.5 mm.

Operating System: Galaxy Nexus runs on the latest version of Google Inc.'s smartphone operating system - Android 4.0 Ice Cream Sandwich - while Galaxy S2 runs on Android 2.3 Gingerbread that is upgradable to Android 4.0.

Processor: Galaxy Nexus is powered by a 1.2GHz dual-core Cortex-A9 CPU, TI OMAP 4460 chipset with 1GB RAM. On the other hand, the Sprint and AT&T variant of the Galaxy S2 is powered by a dual-core 1.2 GHz ARM Cortex-A9 Mali-400MP GPU Orion chipset while the T-Mobile variant is powered by a 1.5 GHz dual-core Qualcomm APQ8060 processor.

Camera: Galaxy S2 scores over Nexus in the camera space as the former has an 8-megapixel camera compared to Galaxy Nexus' 5-megapixel shooter. Galaxy S2 has a 2 megapixel camera on the front for video calling while Galaxy Nexus sports a 1.3-megapixel front-facing camera.

Connectivity: Galaxy Nexus has HSDPA 21 Mbps, HSUPA 5.76 Mbps and 4G LTE support. On the other hand, the T-Mobile Galaxy S2 version has HSDPA 42 Mbps support while the AT&T version has HSDPA 21 Mbps support. And Epic 4G Touch has Rev. A up to 3.1 Mbps.

Wi-Fi/Bluetooth/USB: Galaxy Nexus supports Bluetooth 3.0 version with A2DP along with microUSB 2.0 version, Wi-Fi 802.11 a/b/g/n, dual-band, DLNA and Wi-Fi hotspot.

Galaxy S2 has Wi-Fi 802.11 a/b/g/n DLNA support and an added Wi-Fi Direct feature. Samsung's phone uses 3.0+HS version Bluetooth with A2DP and EDR along with MHL microUSB version 2.0 for HDMI support.

Storage: Galaxy Nexus comes with a fixed 16/32 GB internal storage. Galaxy S2 boasts of 16/32GB internal storage and via a microSD card slot it can be expandable up to 32GB.

Battery: Galaxy Nexus comes with a standard 1750 mAh battery offering talk time of more than 8 hours and standby time of 270 hours in 3G. Samsung Epic Touch 4G has Li-Ion 1800 mAh battery support, which will offer more than 10 hours of talk time while AT&T versions retain Li-Ion 1650 mAh battery found in original Galaxy S2. The T-Mobile variant of Galaxy S2 has Li-Ion 1850 mAh battery support.

Pricing: Galaxy Nexus is available from Verizon for $299.99 with 2-year contract. Galaxy S2 is priced at $199.99 with a two-year contract both on Sprint and AT&T while the T-Mobile variant is priced at $229.99.