IOS signed version refers to the digital signature of the application used on the IOS operating system to ensure the integrity and security of the application. Digital signature refers to the signature file generated by encrypting hash value, which is a kind of authentication method of application program.

Its main function is to enable users to install applications that are not stored in the App Store. Because in Apple's ecological environment, only applications downloaded through the App Store can be considered legal. With the signed version of iOS, users can get some applications that were not originally provided to non-developers or enterprise users, such as iOS development tools.

Although using the signed version of iOS can bring some convenience, there are also some risks. Because these applications have not been officially reviewed by Apple, there may be some security problems or loopholes. Therefore, when using the signed version of iOS, you need to pay attention to the source and avoid downloading unsafe applications to protect the security of your own equipment and information.