Processor: it is very important to pick a device having at least a 1 GHz processor otherwise one might experience noticeable delay. The CortexA8 1GHz or NVIDIA Tegra 1GHz are some popular 1GHz processors.
The display size: Popular display size is 7 inch or 10 inch. This mainly depends on the requirement. If tablet is used for quick web surfing only then one should use 10 inch and if tablet is taken around everywhere to enjoy, then one should definitely use 7 inch version.
Operating System: the Android jellybean or ice cream sandwich are the popular versions that a person should look for. These are known to be much faster than the previous versions and other lower versions cannot be recommended.The internal RAM, Storage, SD slot: the RAM memory should be around 512MB, but higher end or higher priced devices come equipped with 1GB memory. The default storage can vary from 2GB to around 32 GB or even more. But mostly they have external SD card slots which t supports right up to 32GB.
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Internet 3G and scope for Wi-Fi: These two requirements are also depended on how we want to use our tablet. If we want to keep our tablet PC with us all the time, then we would probably prefer to buy the 3G and Wi-Fi supported versions.
Camera / Video recording: Does the tablet have a good camera? Is it a rear one or front one or both? How much is its pixel size? Front camera is very necessary, so that one can do video chat. We must check if tablet supports the 720 HD or the Full HD video recorder.
Touch Screen: a capacitive screen is better than a resistive screen, yet some prefer resistive. The capacitive screen can detect the touch if touched with an electrical conductor like the human body. The resistive screen detects touch only when pressure is detected.
Battery power of tablet: How long does battery last? The iPad usually lasts for up to 10 hours of surfing the web, movies, or listening music. If one can get 10 hours support from any Android device then it comes with very good battery.