What is SpringBoard?
SpringBoard is part of iOS that organizes the home screen and gives you all the options to actions your iDevice can do such as creating folders, changing home screen wallpapers, installing applications, and when you're jailbroken, Activator for SBSettings.
Restarting the user interface without rebooting the phone is referred to as a respring.
What is WinterBoard?
WinterBoard is a Cydia package that allows theming, and is required for 99% of the currently available themes.
What is SummerBoard?
SummerBoard was an earlier theming support package, mostly at this point replaced entirely by WinterBoard.
What is AutumnBoard?
Good question, nobody has invented that one yet.i
How do I get my device out of "Safe Mode" (Springboard crashing)?
Usually a Springboard crash ("Safe Mode") is a temporary problem, where you can tap "Restart" and go back to normal mode.
If your device goes right back into Safe Mode with the same message, you'll need to do some investigation. If you just installed a new tweak, that tweak is probably causing the problem. While you're in Safe Mode, open up Cydia and uninstall the tweak.
If the Springboard crash keeps happening, one or more of your installed tweaks is probably incompatible with your device's version of iOS. Open up Cydia, go to Manage -> Packages, and check the descriptions of each of your installed tweaks to try to find out whether they're compatible with your version of iOS. If one isn't, it's probably the reason for your crash, so uninstall it using Cydia. (Also check your packages to make sure they're all from legitimate sources such as BigBoss, Cydia/Telesphoreo, ModMyi, and ZodTTD/MacCiti; pirated packages frequently cause problems.)
If Safe Mode shows up while you are doing an action that is related to a tweak's functionality, that tweak might be the cause of the crash. Try uninstalling it.
If you have SBSettings installed, you can tap the "More" button and use its "Mobile Substrate Add-ons" feature to temporarily disable some of your tweaks so that you can isolate which one is causing the problem. (Disable some of them, respring, and see if Springboard crashes. If Springboard still crashes, disable some more. If the problem seems fixed, enable some of them. Continue this process until you isolate which one is the cause of the problem.) This is a little faster than uninstalling and reinstalling tweaks using Cydia, but if you use this method, you must make sure to re-enable tweaks before uninstalling them.
If you still can't figure out what's wrong, feel free to post a question and we'll try to help. Make sure to tell us what you did before Safe Mode started happening, what you've tried so far, and a list of your installed packages, to help us guess at what might be wrong.
See also: Cydia's official advice on what to do when you get into Safe Mode.
SpringBoard is part of iOS that organizes the home screen and gives you all the options to actions your iDevice can do such as creating folders, changing home screen wallpapers, installing applications, and when you're jailbroken, Activator for SBSettings.
Restarting the user interface without rebooting the phone is referred to as a respring.
What is WinterBoard?
WinterBoard is a Cydia package that allows theming, and is required for 99% of the currently available themes.
What is SummerBoard?
SummerBoard was an earlier theming support package, mostly at this point replaced entirely by WinterBoard.
What is AutumnBoard?
Good question, nobody has invented that one yet.i
How do I get my device out of "Safe Mode" (Springboard crashing)?
Usually a Springboard crash ("Safe Mode") is a temporary problem, where you can tap "Restart" and go back to normal mode.
If your device goes right back into Safe Mode with the same message, you'll need to do some investigation. If you just installed a new tweak, that tweak is probably causing the problem. While you're in Safe Mode, open up Cydia and uninstall the tweak.
If the Springboard crash keeps happening, one or more of your installed tweaks is probably incompatible with your device's version of iOS. Open up Cydia, go to Manage -> Packages, and check the descriptions of each of your installed tweaks to try to find out whether they're compatible with your version of iOS. If one isn't, it's probably the reason for your crash, so uninstall it using Cydia. (Also check your packages to make sure they're all from legitimate sources such as BigBoss, Cydia/Telesphoreo, ModMyi, and ZodTTD/MacCiti; pirated packages frequently cause problems.)
If Safe Mode shows up while you are doing an action that is related to a tweak's functionality, that tweak might be the cause of the crash. Try uninstalling it.
If you have SBSettings installed, you can tap the "More" button and use its "Mobile Substrate Add-ons" feature to temporarily disable some of your tweaks so that you can isolate which one is causing the problem. (Disable some of them, respring, and see if Springboard crashes. If Springboard still crashes, disable some more. If the problem seems fixed, enable some of them. Continue this process until you isolate which one is the cause of the problem.) This is a little faster than uninstalling and reinstalling tweaks using Cydia, but if you use this method, you must make sure to re-enable tweaks before uninstalling them.
If you still can't figure out what's wrong, feel free to post a question and we'll try to help. Make sure to tell us what you did before Safe Mode started happening, what you've tried so far, and a list of your installed packages, to help us guess at what might be wrong.
See also: Cydia's official advice on what to do when you get into Safe Mode.