render

Checks if the given value is a array, then renders it. If the given value is a string, the string is returned. If you give a non existing value, nothing is returned instead of throwing a error. The array is rendered using the drupal render function.

render(node.field_my_field)

Please note, that under normal circumstances you should have no need to call the render function explicit, because all the variables that you print in a template are looped trough the render method.