When introducing users to the Censys Search Language, this is a question we often hear.
The equals sign means that the value provided as search criteria for a field must be an exact match in totality to the value stored in Censys for the host to be considered a hit. The colon is a “fuzzy” match operator.
To illustrate this, note the differences between results when searching for
services.http.response.html_title="200 Success"services.http.response.html_title:"200 Success"
The first query returned 0 results at the time of this posting as it was looking for exact matches to “200 Success” in the HTML title. The second returned 3 results and included services with responses “200 - Success”.