It means that only the people sending and receiving a message can see what’s inside of it — stopping them from being snooped on by hackers and spies, and even the messaging companies themselves. Encryption works by scrambling up the message in a way that requires a specific key to unscramble it again.
Other apps have capitalised on the feminist zeitgeist, such as Bumble, which puts the onus on the woman by giving her 24 hours to initiate a conversation after she matches with a man. But that doesn’t mean they're not picky about who they’re going to do it with.
Whats App has added end-to-end encryption, and announced it with a little yellow pop-up that reads: "Messages you send to this chat and calls are now secured with end-to-end encryption".
But it's been much less clear about what exactly that means.
How exactly that works depends on the system, and how it is implemented.
But the principle is always the same: using mathematical concepts to ensure that only a sender and a recipient can read any given message. The site has had a form of end-to-end encryption since the end of 2014.
Even the idea of a man asking a woman out is archaic.