Nodes Explaination On Embedded ES with JAVA

All
I have been able to do a search successfully. Here is a sample of my code:
ImmutableSettings.Builder settings = ImmutableSettings.settingsBuilder();
settings.put("path.home","/elasticSearch");
Client client = node.client();
client.prepareIndex("searchdata", "a", String.valueOf(123)).setSource(createJsonForExhibitor(object)).execute().actionGet();

It creates this structure on my drive
/elasticSearch
/data
/elasticSearch
/nodes
/0
/state
metadata-8
shards-13
/indices
/searchdata
/0
/index
/translog
/1
/2
/3
node.lock
/1

What are these all folders for? Can somebody explain to me what are these folders mapped to my index creation?
Thanks