Encryption in Samsung Galaxy S8 Could someone explain what does it mean that Galaxy S8 with Android 7.0 is encrypted by default even when the phone has no password.

I thought it is encrypted because of PIN. And you should type correct PIN to decrypt data.

But I was told that even if phone has no password it is encrypted by default.

By encryption I mean that my phone has protected / unreadable data and I need to somehow decrypt it - by typing the password (pin, pattern, etc).

What does it mean it is encrypted by default ? Right now anybody could take my phone, boot it because it has no password and get access to all my data (photos, movies, sms, etc)
When your device is encrypted (out of the box) and doesn't have a password, it means that - It is encrypted using the OEM encryption algorithm and the hardware characteristics specific to your device (see Trusted Execution Environment ). However, because there is no PIN / pattern lock , one can boot into your device and access data

When you create a PIN/ pattern to permit access to your device, this PIN is used to salt the encryption password and effectively change it. Hence PIN / pattern not only changes your encryption password but also prevents unauthorised access to your device. Everytime you change PIN/ pattern the encryption password is changed