Await expressions

  In "The Python Language Reference, Release 3.13.0a0",
  there is this section:

|6.4 Await expression
|
|Suspend the execution of coroutine on an awaitable object.
|Can only be used inside a coroutine function.
|
|await_expr ::= "await" primary
|
|New in version 3.5.

  . And this is the whole section.

  What I do not understand:

  - Which coroutine is suspended?
  - Which object is the object mentioned?
  - For what purpose is the value of the primary expression used?
  - What does it mean to "suspend something on something"?