[About XDA developers] anandmore:
What is XDA ?

XDA Developers (also known simply as XDA) is a mobile software development community of over 6.6 million members worldwide, started in January 2003. Although discussion primarily revolves around Android, members also talk about many other operating systems and mobile development topics.

Why XDA ?

The site's main purpose is discussion, troubleshooting and development for Android, Sailfish OS, Windows Phone, WebOS, Ubuntu Touch, Firefox OS and Tizen phones. The site also offers Windows Mobile and Android users general information about devices, ROM upgrades, technical support, Q&A, and reviews of device applications and accessories. Separate forums exist for each model of phones manufactured by Micromax Mobile, Sony, HTC, Samsung, LG, Motorola, and many others. Forums are also available for tablets and many other devices.

What is Rooting ?

Rooting is the process of allowing users of smartphones, tablets and other devices running the Android mobile operating system to attain privileged control (known as root access) over various Android subsystems. As Android uses the Linux kernel, rooting an Android device gives similar access to administrative (superuser) permissions.

Source : Rooting (Android OS)

Why should i root my phone ?

Rooting is often performed with the goal of overcoming limitations that carriers and hardware manufacturers put on some devices. Thus, rooting gives the ability (or permission) to alter or replace system applications and settings, run specialized applications ("apps") that require administrator-level permissions, or perform other operations that are otherwise inaccessible to a normal Android user. On Android, rooting can also facilitate the complete removal and replacement of the device's operating system, usually with a more recent release of its current operating system.

In simple words, rooting gives you superuser access and you can modify your device as you want to.

What is Custom Recovery ?

Android custom recovery image. Once installed, this recovery image replaces your Android device's stock recovery image. Using this recovery image, you can do various system-level operations on your phone. For example, you can create and restore backups of your phone's built-in storage, root your device, install / repair / upgrade system software and/or custom ROMs, and use other developer tools.

In simple words, In order to flash the custom ROMs or Mods for your device, you need custom recovery indtalled on your device.

What is ROM ?

ROMs are aftermarket Android distributions. They are often used to add new features to a phone or to gain new versions quicker.

In simple words, the user interface and everything you see is Rom.

What is Stock Rom ?

A stock ROM is the ROM that comes with a device; the device is "stocked" with that ROM by the manufacturer. Android is generally customized by the manufacturer to some degree; at minimum there needs to be device-specific drivers and so on for Android to work on a particular device. As Flow notes, customizations may include a custom theme, launcher, and default apps like HTC Sense does.

In simple words, The operating sytem that comes pre-installed when you buy the phone is Stock Rom.

What is Custom ROM ?

A custom ROM is a modified version of the Android operating system. Tweaks, additional features, different themes or an enhanced performance are usually included. Custom ROMs also offer the possibility to use a newer, unreleased, version of Android on your phone that might usually not be available for your device because of restrictions from manufacturer or providers.

In simple words, these Roms are made by developers that let you customize and tweak your mobile phone.

What is Kernel ?

The kernel is the brain of your phone that controls how the system and hardware interact. It’s basically the lowest level of your operating system that manages memory and hardware.

What is NANDroid Backup ?

A NANDroid backup is a complete system backup of your Android device. This backup can be restored later and might save your phone after flashing a faulty ROM or theme.

What is Recovery Mode ?

Recovery mode offers you the possibility to perform system-level tasks (like formatting, defragmenting, etc.), backing-up your devices or install custom ROMs. Android offers a limited stock recovery function. More sophisticated recoveries like ClockworkMod Recovery and TWRP Recovery offer additional features and are easier to use.