While searching the StackExchange for 'Queued' I found that most answers are related to apex code. In my case I'm using the SalesforceBulk API (through python).
My scenario: When calling the batch_status(job_id, batch_id) method, in most cases I'm getting 'State': 'Completed', but from time to time I'm getting State': 'Queued'.
How to relate to state? I couldn't understand from the documentation if those jobs will get out of the queue automatically and I just need to check the status from time to time, or should I trigger something to get them out of the queue and to be processed.