Jailbreaking is the process of removing restrictions imposed by the manufacturer on a smartphone, allowing the user to install unauthorized software and features not available through official app stores. This action typically voids the warranty and can introduce security risks by bypassing built-in protections. * SOU (Statement of Understanding) is not related to modifying devices. * Cross-site scripting is a web-based attack technique, unrelated to smartphone software. * Side loading refers to installing apps from unofficial sources but without necessarily removing built-in restrictions like jailbreaking does.