Standard and Advanced agents works same, but when it comes to Auto queue management Advanced agents comes under the picture.
Standard agents are generally we use in our systems. When it is processing some list of records in the system, if any record failed then it moved to broken queue. Then if you want to process that record then you need to go SMA and under Agents and process link you can see all the broken process. So again if you want to process them you need make them requeue.