# Tags vs Fields
**URL:** https://discuss.elastic.co/t/tags-vs-fields/24014
**Category:** Logstash
**Created:** [June 19, 2015, 7:48pm UTC](https://discuss.elastic.co/t/tags-vs-fields/24014 "2015-06-19T19:48:14Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@michaellizhou](https://discuss.elastic.co/u/michaellizhou)
#### Post date: [June 19, 2015, 7:48pm UTC](https://discuss.elastic.co/t/tags-vs-fields/24014/1 "2015-06-19T19:48:14Z")
Here is a simple question yet I do not know the difference: what is the difference between a tag and a field?
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [June 20, 2015, 3:49am UTC](https://discuss.elastic.co/t/tags-vs-fields/24014/2 "2015-06-20T03:49:49Z")
A field is a subset of the event/document.
A tag is an attribute you can apply to either do conditional based filter on, or to make it easier for searching.
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### Author:  [@michaellizhou](https://discuss.elastic.co/u/michaellizhou)
#### Post date: [June 22, 2015, 1:53pm UTC](https://discuss.elastic.co/t/tags-vs-fields/24014/3 "2015-06-22T13:53:39Z")
Still confused probably both can be used to quickly query for a specific attribute. Does this mean I should only add fields when I do not need to do conditionals in my filter? Otherwise if i just need to quickly search I can do it through a field? Or if my purpose is to find an event, on say kibana, I should use a field or tag? Thanks
Mike
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### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [June 22, 2015, 2:17pm UTC](https://discuss.elastic.co/t/tags-vs-fields/24014/4 "2015-06-22T14:17:46Z")
> Still confused probably both can be used to quickly query for a specific attribute.
Yes.
> Does this mean I should only add fields when I do not need to do conditionals in my filter? Otherwise if i just need to quickly search I can do it through a field? Or if my purpose is to find an event, on say kibana, I should use a field or tag?
Either way, really. Tags are a way of attaching boolean values to events, i.e.
```
{
"tags": [
"foo",
"bar"
]
}
```
isn't much different from this:
```
{
"foo": true,
"bar": true
}
```
Apart from the obvious difference in syntax there's another thing: In the latter case a new "tag value" created as a field will affect the mapping of the type but adding a new string to the `tags` list (which is just a regular Logstash field) won't.
In the end a tag is just a special-purpose field used as a shorthand for slapping, well, a tag onto a document.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 5:36am UTC](https://discuss.elastic.co/t/tags-vs-fields/24014/5 "2017-07-06T05:36:52Z")