iPhone | Dictionary of iPhone TerminologyHere is a dictionary of iPhone terms to help you understand the words commonly used in the iPhone community.
ActivationWhen you first purchase your iPhone all you can do is call 911 until you activate with AT&T (or similar). If you are using an official Apple carrier carrier then you can activate through iTunes; otherwise you will have to perform a hack to activate your iPhone. Once activated it becomes an iPod touch with camera and bluetooth at which point you will want to proceed to jailbreak and possibly unlock it for use on other carriers.
BasebandThe Baseband controls the interaction between the Phone part of the iPhone and the operating system. Whenever the iPhone needs to talk to cell towers-- whether for voice or data-- it works through the Baseband. The Baseband is responsible for making sure the sim-card is valid and for getting Signal. When you unlock your iPhone the baseband is modified to allow communication to other wireless carriers. The latest baseband version is 04.04.05_G and it corresponds to the 1.1.4 firmware.
BootloaderThere are at least two bootloaders in the iPhone. One is the ARM Core Bootloader and deals with the Operating System, the other is the Baseband Bootloader. Bootloaders make sure that when the iPhone boots it is doing things in the right order, and getting everything done. Currently the iPhone has shipped with two different Baseband Bootloaders (3.9 and 4.6). The 3.9BL allowed us to load a hacked baseband which matches the firmware version. Apple changed this feature in the 4.6 BL and made it require a baseband of a newer firmware version. This is why the Dev Team has released a 3.9 fakeblank BL which allows you to load a hacked baseband matching your firmware version.
DFU ModeDFU means Device Firmware Update. If a restore using Recovery Mode doesn't work you will want to use DFU Mode as a last resort. When placing your iPhone into DFU Mode it does not load the OS before attempting the restore. Hold the Sleep/Wake and Home buttons for 10 seconds. Just before you would normally see the Apple logo, release the Sleep/Wake button and keep hold the Home button until an iTunes detects an iPhone in recovery mode. NOTE**: This is really tricky to get the timing right it will take a few attempts. If you are in DFU Mode your screen will be black with nothing displayed.
FirmwareThe firmware version you have installed on the iPhone is similar to the version of the operating system on your computer. Newer firmware versions usually add new features, fix bugs, and improve stability. iPhones first shipped with 1.0.x firmware. iPhones now are shipping with 1.1.4 and version 1.2 (2.0 Beta) is available to select developers.
Installer.appInstaller.app is a UIKit based package manager for the iPhone. It works by downloading packages over WiFi (wireless networking) or EDGE. It supports installing, updating and uninstalling applications from multiple sources. You will use Installer.app to install a majority of your iPhone applications.
JailbreakThe process of gaining access to the iPhone's root filesystem, allowing third-party applications to run on the device. In general once you jailbreak you will have Installer.app, Cydia, or Icy on your SpringBoard. You can use these utilities to install most every application you would need on your iPhone.
OOB or OTBUsed to refer to the firmware version your iPhone came with "Out of the Box". ie. If you have a 1.1.2 OTB iPhone that means your iPhone came with the 1.1.2 firmware preinstalled.
Recovery ModeIf you want to do a clean restore you can put your iPhone into recovery mode to do so. Hold the Sleep/Wake and Home buttons until the iPhone reboots. Once you see the Apple logo, release the Sleep/Wake button and keep hold the Home button until an iTunes logo and the usb cable appear on screen. You can then use iTunes to restore your firmware.
SecpackA Secpack is similar to a password for the Bootloader. When passed to the bootloader, it authorizes write access to the Baseband.
SDKSDK is short for Software Development Kit and it's basically a library of software that helps you develop applications and utilities. Apple has just released the iPhone SDK which is the set of tools needed to create applications that run on the iPhone.
UnlockThe process of Unlocking allows your iPhone to use any GSM sim card. Currently Apple has limited the use of the iPhone to a select few wireless carriers. The iPhone must be unlocked before you can use any carrier of your choice.
What is Cydia?Cydia is similar to installer, in that it’s a package management system for the iPhone/iPod Touch, written by Jay Freeman (Saurik), but in reality it’s a whole lot more than that; Cydia is a graphic user interface for APT on the iPhone/Touch.
APT or ‘Advanced Packaging Tool,’ is the main package distribution system for Linux systems, and has been ported to many others including UNIX, Mac OS X (available in Fink), and now the iPhoneOS! There are many APT front-ends for Linux and other systems including ‘aptitude,’ and ‘Synaptic Package Manager.’ This is basically what Cydia is to the iPhone. (This also means that you can apt-get any of the cydia packges from a terminal window or ssh, right *on* the phone)
Jay Freeman (Saurik) writes on his website:“In general, Cydia works very similarly to Installer, allowing people to quickly get up and running with the newer software. The main interface component is a bar of buttons along the bottom that provide access to the different main screens of the application.”
For the most part, Cydia is just like installer in terms of user interface, with a few exceptions. The ‘Updates’ tab has been renamed to ‘Changes,’ where all of the packages updates *and* new packages are listed. Updates are located at the top whereas new packages are listed below, in reverse chronilogical order; this replaces the ‘Recent Packages’ category in Installer. The second main differance is the ‘Uninstall’ Tab has been renamed to ‘Manage,’ which is actually much better fitting. Not only can you browse and uninstall all of the applications and utilites that you currently have installed, but you also have the option to reinstall them, all from one screen. This means no more uninstalling from one tab, and having to go back any find the applications you wish to install again from another.
The final difference between Installer.app and Cydia is the sources editor. You may notice that in Cydia, well, there isn’t one. Truth is it’s being still being worked on, but had to be placed on the backburner due to all of the 2.0 and Pwnage drama that arrised in the last software update. The goal is for the sources editor to be placed in Settings.app, instead of having it clutter up Cydia itself, and is now a priority and should be finished soon.
Note: If you know more feel free to add 
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