Query about fields in Solr

I'm very new to Solr and I'm looking at someone else's code. I'm looking at the schema.xml and found the following:开发者_JS百科

1. field
2. dynamicfield
3. copyField

What is the difference between these please?

Thanks! :)

Krt_Malta

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They're all thoroughly explained in the Solr wiki.

Also here's a blogpost about dynamicFields, and here's another one about copyFields, they might help.