Document how this returns bytes
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index 5852dc2..a0e7650 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -63,6 +63,11 @@
:param bytes data: The data you wish to pass into the context.
:return bytes: Returns the data that was encrypted or decrypted.
+ When the ``BlockCipher`` was constructed in a mode turns it into a
+ stream cipher, this will return bytes immediately, however in other
+ modes it will return blocks in chunks, whose size is determined by the
+ cipher's block size.
+
.. method:: finalize()
:return bytes: Returns the remainder of the data.
@@ -162,7 +167,8 @@
block size of less than 128-bits.
CTR (Counter) is a mode of operation for block ciphers. It is considered
- cryptographically strong.
+ cryptographically strong. It transforms a block cipher into a stream
+ cipher.
:param bytes nonce: Should be random bytes. It is critical to never reuse a
``nonce`` with a given key. Any reuse of a nonce