Fix typo and clarily that a server function reference is created only when that function is used by a Client Component

Author: kapantzak

src/content/reference/rsc/server-functions.md

@@ -28,7 +28,7 @@ To support Server Functions as a bundler or framework, we recommend pinning to a
 
 </Note>
 
-When a Server Functions is defined with the [`"use server"`](/reference/rsc/use-server) directive, your framework will automatically create a reference to the server function, and pass that reference to the Client Component. When that function is called on the client, React will send a request to the server to execute the function, and return the result.
+When a Server Function is defined with the [`"use server"`](/reference/rsc/use-server) directive and is used by a Client Component, your framework will automatically create a reference to the Server Function, and pass that reference to the Client Component. When that function is called on the client, React will send a request to the server to execute the function, and return the result.
 
 Server Functions can be created in Server Components and passed as props to Client Components, or they can be imported and used in Client Components.