adds some details to at-async and tweaks at-schedule doc

base/docs/helpdb.jl

@@ -2384,7 +2384,7 @@ promote
 doc"""
     @schedule
 
-Wrap an expression in a `Task` and add it to the scheduler's queue.
+Wrap an expression in a `Task` and add it to the local machine's scheduler queue.
 """
 :@schedule
 
@@ -4672,7 +4672,7 @@ erfinv
 doc"""
     @async
 
-Wraps an expression in a closure and schedules it to run on the local machine. Also adds it to the set of items that the nearest enclosing `@sync` waits for.
+Like `@schedule`, `@async` wraps an expression in a `Task` and adds it to the local machine's scheduler queue. Additionally it adds the task to the set of items that the nearest enclosing `@sync` waits for. `@async` also wraps the expression in a `let x=x, y=y, ...` block to create a new scope with copies of all variables referenced in the expression.
 """
 :@async
 

doc/stdlib/parallel.rst

@@ -97,7 +97,7 @@ Tasks
 
    .. Docstring generated from Julia source
 
-   Wrap an expression in a ``Task`` and add it to the scheduler's queue.
+   Wrap an expression in a ``Task`` and add it to the local machine's scheduler queue.
 
 .. function:: @task
 
@@ -401,7 +401,7 @@ General Parallel Computing Support
 
    .. Docstring generated from Julia source
 
-   Wraps an expression in a closure and schedules it to run on the local machine. Also adds it to the set of items that the nearest enclosing ``@sync`` waits for.
+   Like ``@schedule``\ , ``@async`` wraps an expression in a ``Task`` and adds it to the local machine's scheduler queue. Additionally it adds the task to the set of items that the nearest enclosing ``@sync`` waits for. ``@async`` also wraps the expression in a ``let x=x, y=y, ...`` block to create a new scope with copies of all variables referenced in the expression.
 
 .. function:: @sync