There are two types of jailbreaking to be aware of - and while we strongly only recommend untethered - you should be aware of both:

• Tethered jailbreaking - this type of jailbreaking requires you to plug your iPhone into your computer to boot it as a jailbroken device.... every time. Then once you shut it off or stop the direct connection, the device resets itself.
• Untethered jailbreaking - is the more preferred and common form of jailbreak allowing you to be able to use your iOS device without being connected to a computer at all times.