What is the difference between @timestamp and timestamp?

[Kramer_Li]

Thanks very much. I posted another question here

[@timestamp] is used by multiple types. Set update_all_types to true to update [format] across all types

I have a template as below: curl -XPUT localhost:9200/_template/template_flow_detail -d ' { "template" : "flow_detail_*", "mappings" : { "traffic" : { "properties" : { "@timestamp": { "index": "not_analyzed", "type": "date","format": "epoch_second"}, "router_ip" : { "type" : "integer", "index" : "not_analyzed"}, "interface" : { "type" : "integer", "index" : "not_analyzed"}, "src_i…

Is it possible for you to have a look also? Thanks very much