Jailbreaking

Jailbreaking is the act of allowing unapproved code to run on iDevices. You might think that this is bad, as unapproved code can be malicous.

However, it usually isn't in the case of jailbreaking. There are many motives, most of which are good.

Motives
So, as I mentioned, there are many motives. Some of which are:


 * Installing tweaks to customize the device.
 * Downloading and installing unoffical apps, which arent on the appstore.
 * Gaining additonal privleges.
 * Dual or mutli booting to run additonal (i)OS versions.

Many of these motives aren't bad.

Now we get to the more questionable but not nesseracly malicous motives:


 * Piracy, which is obtaining things that you didn't pay for.
 * Cheating in mobile games.
 * Disabling restrictions like parental controls.
 * BIG ONE: bypassing or mitigating activation lock or other issues like that.

These motives usually aren't malicous. For example, someone might bypass activation lock on a device that they brought or were given.

Types of jailbreaking
There are 4 major types of jailbreaking.

They are untethered which you can reboot and let the battery die as much as you want and still be jailbroken. These aren't too common anymore because of new mitigations inplemented by Apple.

Tethered jailbreaks are the opposite, requiring you do boot with a PC. These just stink, thank goodness they aren't around anymore. There mostly good for developers only.

Semi-Tethered jailbreaks allow you to boot all you want, but you can't use the jailbreak without a PC. These died when bootloader exploits weren't a thing, but came back when they became a thing again.

Semi-Untethered jailbreaks allow you to boot all you want, and you can jailbreak without a PC, but it requires an app (or website) on the device. This is typically sideloaded via a PC, a website that can be entered, or an app from a signing service. These are the most common jailbreaks now as they use less powerful exploits.

What you can do with a jailbreak
You can do the following but you are not limited to just that:


 * Install tweaks to customize your iDevice, Such as digitalbattery13. You can also ask around, or find tweaks yourself.
 * Install apps not avalible in the app store, you can do this via sideloading, but jailbreaking can make things better.
 * Gaining additonal privleges, like shell access.
 * Testing and debugging apps easier.
 * Bringing new features to older devices and OS versions.
 * Dual-booting.

Some things can be used for malicous things. Such as unoffical apps can have malware, or be pirated. Some things could cause issues for devices, requiring an unjailbreak or a full restore. An example is say a bad tweak could cause issues with your jailbreak. There are some issues as well that are inherit. For example, you don't awlays know what your installing. Say if you install a tweak that came from some small repo, it could be poorly-made, or it could be malicous. Now, I'd say look to see what tweaks are safe and good, ask around. Another issue is that in most cases, you have to use an older version of iOS. The primary reason is that exploits often get patched, often before they are even released to the public.