Neither of those statements are true. Telegram's server software is proprietary, so it doesn't matter that the clients are free software. Conversations on Telegram are all sent unencrypted by default and are stored on Telegram's proprietary servers, whereas conversations on WhatsApp are encrypted with the Signal protocol, always and everywhere. WhatsApp may be the worst thing to happen to communication since Facebook, but at least they don't pretend to be anything else. Telegram are a bunch of phonies. Don't use Telegram. (You could use Signal instead. It works on Android, iOS, your desktop and even on Sailfish!)