Merge pull request #39860 from hahmed/docs/actiondispatch-cookies-improvements

Update wording for cookies [ci-skip]

actionpack/lib/action_dispatch/middleware/cookies.rb

@@ -88,11 +88,10 @@ def use_cookies_with_metadata
     # :startdoc:
   end
 
-  # \Cookies are read and written through ActionController#cookies.
+  # Read and write data to cookies through ActionController#cookies.
   #
-  # The cookies being read are the ones received along with the request, the cookies
-  # being written will be sent out with the response. Reading a cookie does not get
-  # the cookie object itself back, just the value it holds.
+  # When reading cookie data, the data is read from the HTTP request header, Cookie.
+  # When writing cookie data, the data is sent out in the HTTP response header, Set-Cookie.
   #
   # Examples of writing:
   #

actionpack/lib/action_dispatch/middleware/session/cookie_store.rb

@@ -10,8 +10,8 @@ module Session
     # dramatically faster than the alternatives.
     #
     # Sessions typically contain at most a user_id and flash message; both fit
-    # within the 4K cookie size limit. A CookieOverflow exception is raised if
-    # you attempt to store more than 4K of data.
+    # within the 4096 bytes cookie size limit. A CookieOverflow exception is raised if
+    # you attempt to store more than 4096 bytes of data.
     #
     # The cookie jar used for storage is automatically configured to be the
     # best possible option given your application's configuration.