activemq - What does failover transport do with a single URI -

What is the difference between specifying when I specify which broker to connect to my active MQ client?

  tcp: // host: port   
 and  
  failovers: (tcp: // host: port)   
 I tried to stop and start the broker and in both cases the customer finds the broker again after restarting. I have not used the messages in the flow (I am using queues) or with other network failures so far to see if there is any difference  
 Hopefully someone has a definite answer Is because the documentation I found is a bit unclear.  
 Thanks   
 
 
 Failover protocol also allows you to provide some useful connection parameters. For pre:  
  failover: (tcp: // host: port)? Jms.useAsyncSend = true & amp; Timeout = 5000   
 here will be sure to bail out the initial connection attempt after 5 seconds if the broker is not available or is not responding after 5 seconds.