docs: added some clarification on serverless functions getting executed in a non-serverless environment (#9742)

Closes #9741.

---------

Co-authored-by: Dominic Saadi <[email protected]>

Author: suzdalnitski

docs/docs/auth/supertokens.md

@@ -11,6 +11,13 @@ yarn rw setup auth supertokens
 ```
 
 This installs all the packages, writes all the files, and makes all the code modifications you need.
+
+:::info
+
+You may have noticed that in `api/src/functions/auth.ts` there's an import from `'supertokens-node/framework/awsLambda'`. This is fine, even if your app isn't running in a serverless environment like AWS Lambda. In "serverful" environments, Redwood automatically handles the translation between Fastify's request and reply objects and functions' AWS Lambda signature.
+
+:::
+
 For a detailed explanation of all the api- and web-side changes that aren't exclusive to SuperTokens, see the top-level [Authentication](../authentication.md) doc.
 For now, let's focus on SuperTokens's side of things.
 

docs/docs/serverless-functions.md

@@ -2,10 +2,19 @@
 description: Create, develop, and run serverless functions
 ---
 
-# Serverless Functions
+# Serverless Functions (API Endpoints)
 
 <!-- `redwood.toml`&mdash;`api/src/functions` by default.  -->
 
+
+:::info
+
+You can think of serverless functions as API Endpoints, and in the future we'll update the terminology used.
+
+Originally, Redwood apps were intended to be deployed as serverless functions to AWS Lambda. Whenever a Redwood app is deployed to a "serverful" environment such as Fly or Render, a Fastify server is started and your Redwood app's functions in `api/src/functions` are automatically registered onto the server. Request adapters are also automatically configured to handle the translation between Fastify's request and reply objects to the functions' AWS Lambda signature.
+
+:::
+
 Redwood looks for serverless functions in `api/src/functions`. Each function is mapped to a URI based on its filename. For example, you can find `api/src/functions/graphql.js` at `http://localhost:8911/graphql`.
 
 ## Creating Serverless Functions
@@ -34,12 +43,6 @@ export const handler = async (event, context) => {
 }
 ```
 
-:::info
-
-We call them 'serverless' but they can also be used on 'serverful' hosted environments too, such as Render or Heroku.
-
-:::
-
 ## The handler
 
 For a lambda function to be a lambda function, it must export a handler that returns a status code. The handler receives two arguments: `event` and `context`. Whatever it returns is the `response`, which should include a `statusCode` at the very least.