Accelerometer. A tiny 3-axis device that monitors the iPhone’s position in it’s envorinment. Basically it can tell which way it is being held or rotated. You can buy one here for $9.93 USD.

Activation. 1. The process that allows you to move beyond any of the various screens that instruct you to connect your device to iTunes before it can be used. On the iPhone, you can only make emergency calls until your iPhone is activated. 2. Out the box, the iPhone doesn’t do much except look pretty and make emergency calls. Activation gives access to normal operation. Typically this is accomplished using iTunes, by obediently signing up for service with official carrier AT&T. But if the world comprised of only obedient people, we wouldn’t be here today. With buggered-up iPhones.
Baseband. The part of an iPhone’s memory that provides the firmware for the phone’s radio modem chip.

Bricking, Brick. 1. To render an iPhone or iPod touch inoperable. The 1.1.1 firmware update turned many iPhones into iBricks. Users could not reactivate their iPhone to get past their “Please connect to iTunes” screens. Although the phones could still be used for emergency calls, users were locked out from all normal iPhone operations. 2. Traditionally, “bricked” hardware is that which becomes permanently inoperable, especially due to a failed firmware update or attempt at modification. With an iBrick, however, the term is somewhat broader — many bricked iPhones still fire up, but are effectively unusable for one reason or another. The good news is that they may be recovered without messing with hardware. The bad news is that you still can’t call mom until someone figures out how.

DevWiki. The developer wiki for iPhone is hosted at iPhone.fiveforty.net. Many developer projects first appear here and the site contains a wealth of iPhone and iPod touch related information. The iPod touch Developer Wiki contains many of the most important recent developments regarding the touch. The phrase DevWiki may refer to either of these two sites.

/etc/fstab. The file on your iPhone or iPod touch that states whether your file system allows read-write access.

emulator. A program that allows a computer or modern console to emulate a video game console.

File system. The way your iPhone or iPod touch uses its memory to store data and applications. The iPhone and iPod touch use two “disks”: a smaller private file system that contains the operating system and a larger public one that contains your media (songs, videos, etc), preferences, and data.

Firmware. the iPhone’s built-in programming, embedded into memory set aside for this purpose. Apple releases periodic updates to this code, and it’s a combination of earlier unauthorized modifications and official update number 1.1.1 that led to the current “iBrick” situation. To hardware grognards, the dangers of injudicious firmware fiddling are well-known but Apple’s made the process of updating simple and straightforward — at least for those who toe the line.

GSM. Global System for Mobile Communications, a popular mobile phone standard used by the iPhone.

Hacks. This refers to all the adventures herein, be they baffling text commands or GUI applications. So called “jailbreaks” provide beach-head access to the system in juicy anticipation of further hacking. Other hacks activate the phone for general use without forcing the user to go through the official process. Others unlock the phone from AT&T’s mobile network (two popular examples are iPhoneSimFree and AnySIM), while others make easy the installation of unofficial software.

iDevice: This can refer to any of the 3 devices made by Apple that starts with the small letter “i” including all generations of the iPhone, iPod touch or iPad.

Jail. The public areas of the iPhone or iPod to which, by default, Apple allows read/write access via USB. In Unix terms, this refers to the /private/var/root/Media folder.

Jailbreak. 1. The iPhone and iPod touch hacks that allow users to gain access to the entire Unix filesystem. In Unix terms, this refers to changing the root of the directory tree to /. 2. a hack that gains access to areas of the iPhone that users aren’t supposed to mess with. Typically, this is an immediate prelude to either installing cool programs, unlocking the handset for use with another cellular network, or both.

SIM lock. A limitation imposed by the manufacturer of a GSM phone to limit a phone to certain carriers. The US iPhone is SIM locked and can only be used with AT&T.

Springboard. iPhone default application launcher. Basically this is the stock software that runs your home screen where you launch all your applications.

ssh. Secure shell. This is a shell that runs on your iPhone or iPod touch using port 22 and allows you to connect wirelessly to a Unix shell.

Third party apps. 1. iPhone and iPod touch applications that were neither created by nor commissioned by Apple. 2. The programs which run on the iPhone. While anyone with the coding chops can write a web-based application for use on the iPhone’s Safari browser, developers crave access to the phone itself—access that Apple has not yet provided. So-called “native” apps are faster, better, and allow access to iPhone functions that Safari does not. Many iPhone users are happy with official carrier AT&T and hack their handsets simply to run these programs.

Toolchain. In terms of the iPhone/iPod touch world, a compiler and linker developed by Patrick Walton of the University of Chicago and his compatriots. It allows developers to create applications that can run on the iPhone and iPod touch’s ARM processor.

Unlock. 1. Bypassing a phone’s SIM lock to allow it to be used with any carrier with compatible equipment. In the US, the iPhone is compatible with both AT&T and T-Mobile’s GSM equipment. 2. You can often pay a premium to buy a phone untethered to a particular carrier. Apple’s iPhone is not such a phone. Cupertino developed powerful and complex locking systems to prevent you from leaving AT&T’s cold embrace. Though unofficial unlocking solutions soon arrived, it was these unlocked iPhones that faced the worst problems after Apple’s official 1.1.1 firmware update.

Unlocking Software. Software that allows the iPhone to be unlocked. You must jailbreak a phone in order to install and use unlocking software.