Divorce

A Divorce is the certified ending of a marriage and once a Divorce had been granted (once it becomes final) you can then legally remarry. 
Before you can make an Application for Divorce you must have been formally separated from your partner for at least a 12 month period.  This does not mean that you have necessarily been living in a separate house; you can have been separated under the one roof.  The Court will not care about who is at fault for the breakdown of the marriage, they will only need confirmation that you have been separated for the minimum 12 month period and that there is no likelihood that you and your partner will reconcile.
You will also need to establish that you are an Australian citizen, live in Australia and regard it as your permanent residence or normally live here and have done so for 12 months prior to the Application being made.
A Divorce does not resolve the issues relating to the living arrangements of the children nor does it deal with property division.  You need to sort out those matters in other ways.  Speak to Duane Portway Family Law about this.