Elixpath.Access.query

You're seeing just the function query, go back to Elixpath.Access module for more information.
Link to this function

query(data, key, opts)

Specs

query(data :: term(), key :: Elixpath.Tag.wildcard() | term(), opts :: list()) ::
  {:ok, [matched :: term()]} | {:error, reason :: term()}

Fetches all children that matches key from data.

key can be Elixpath.Tag.wildcard() (i.e. :elixpath_wildcard), which stands for "all the children"