mongoose - elasticsearch/mongoosastic : what is the differences between es_indexed and es_type -

i needed implement search in app found elasticsearcha , mongoosastic using mongoose crud mongodb.

follow steps provided here indexing many fields in model , works fine. before put in action wanted figure out difference between

title: {type: string, es_indexed:true} description: {type: string, es_type:'string'} 

iv'e figure out using es_boost:2.0 example give high proiorty.

string: {type:string, es_boost:2.0}