A user would like to install software and features that are not available with a...

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​​.