Semi-Untethered
Examples: Dopamine, unc0ver
- Device boots normally after a restart — no computer, no special boot mode
- Run an app on the device itself to re-jailbreak
- Most convenient option for daily use
Semi-Tethered
Examples: palera1n, checkra1n
- Device also boots normally after a restart
- Needs a computer to re-apply the jailbreak each time it reboots
- More stable across newer iOS versions; the standard approach for checkm8 devices
Untethered
Rare on modern iOS
- Stays jailbroken through a restart with zero action needed
- Effectively extinct on current-generation exploits
Recommendation: use a semi-untethered tool if one exists for your device and iOS version — it's the least hassle. Fall back to semi-tethered if that's the only option available for your hardware.