According to an Apple security page, 13.5.1 for iPhone and iPad contains a fix for the exploit found by the jailbreaking team unc0ver on 21 May that allowed people to successfully jailbreak devices running iOS 13.5. Unlike Android, Apple does not encourage the modification of iOS and works to keep jailbreaks from happening, often claiming they compromise security.
Jailbreaking an iPhone lets you do things like change the appearance of icons and the system like you can with Android launchers and personalise your iPhone’s software more than Apple usually allows.
The Apple Watch software watchOS has also received update 6.3.6 and contains mainly security updates.
Henry is Tech Advisor’s Phones Editor, ensuring he and the team covers and reviews every smartphone worth knowing about for readers and viewers all over the world. He spends a lot of time moving between different handsets and shouting at WhatsApp to support multiple devices at once.