URL Search, What is the difference between colon and equal?

Question

I found that Elasticsearch returns the same results for following queries.

twitter/_search?q=user:kimchy

twitter/_search?q=user=kimchy

However, If I query for nested object, Elasticsearch will return different results

twitter/_search?q=location.address:us

twitter/_search?q=location.address=us

What do colon and equal mean in term of Elasticsearch?

Answer 1

The = sign is part of the URL to separate the parameter and values in the query string.

The : sign is part of the Lucene query expression language and is always used in the q= parameter of the query string.

So the first queries above are correct but not the second ones, even though they return data.