MQTT " the new one " WHAT / HOW?

“There is only one Bridge Thing per connection to an MQTT Broker. You should only have the one Bridge Thing”

I have this Thing file and at the top :

Bridge espmilighthub:esp8266Bridge:001 "ESP Milight Bridge" @ "espmilighthub" [ADDR="tcp://10.0.0.53:1883"]

And i have this Thing file and at the top :

Bridge mqtt:broker:mqttBroker "broker    : mqtt broker" [ host="10.0.0.53", secure=false]

1 : Is this 2 connections or 2 brokers ?
( I have it all working but don`t realy know how ,and i wood like to know if there is a fault )

2 : My biggest problem is that i cant and haven't gotten the syntax in the "new" or "old" mqtt and im not a coder at all ,so my “old” mqtt connection looks like this :

mqtt.cfg :

broker.url=tcp://10.0.0.53:1883

pid:org.openhab.mqtt

sonoff.items :

Switch back_door  "back_door" <back_door> (BA)  ["Switchable"] 
  { mqtt=">[broker:cmnd/back_door/power:command:*:default],
          <[broker:stat/back_door/POWER:state:default]" ,autoUpdate="false"  }

And i have no ideer how my new Bridge Things file line shot look like so the “new” and “old”
broker is the same and not conflicting, that’s why i made the picture above ,just to understand what is what.

Bridge mqtt:broker:mqttBroker "broker    : mqtt broker" [ host="10.0.0.53", secure=false]