2011 was a year of great changes and shake-ups for the mobile landscape. Samsung finally overpowered Apple as the world’s top smartphone maker in the July-September period, toppling everyone's favorite fruit from its throne. With last year's introduction of the iOS 5-flavored Apple iPhone 4S and Android 4.0 Samsung Galaxy Nexus, the competition is all set to be hotter between the Big Two this year.

The Nokia Lumia 800 and 710 Windows Phone 7.5 devices made their debut late last year as well, adding more variety and competition to the mobile line-up. While Research in Motion (RIM) had nothing much to show for their newly-announced BlackBerry 10 OS, details revealed this year unveiled much promise about a revamped UI and radical design changes.

2011 might have been the year for dual-core smartphones, but 2012 is set to be the year for more powerful, less battery-sapping quad-core smartphones such as those based on the NVIDIA Tegra 3. 

We know the challenges involved in choosing a smartphone. Do the latest mobile operating systems have the chops to get things running? Are you looking at a larger display on your smartphone? Does a faster processor speed and more cores matter? How do all these factors tie together in the big picture? All that, shall be answered in HardwareZone's Smartphone Buying Guide Essentials. Check out the jump links to the right to dive into the details.

• Choosing a Price Plan
   
• Operating System: Finding the Right Platform
   
• Processor: The Brains of the Operation
   
• Memory & Storage: More is Better
   
• Display: Size Does Matter
   
• Camera Quality: Concerns For the Shutterbugs
   
• Connectivity Options: Get the Correct Link
   
• Battery: All Juiced Up
   
• Choosing the Right Smartphone