A Comparison Type determines how the 2 Filter does its filtering. 

A filter's Comparison Type is defined during the creation of the filter:

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This Comparison Type is unique. All 2 Filters with a FreeText Comparison Type are gathered into a single filter with an 1 ID of "freetext". 

Here is an example to help you grasp the concept:

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Due to the inner workings of how such filters work, any search, which has a freetext filter, MUST be populated (see UseSolr for a guide on how to populate a search).

Equals

Tests whether a 2 Filter's parameter matches exactly with the data, the filter works on.

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The same as Equals, but treats a value of "null" 0" as nullas "0", where "0" is of data type bit, ie "1" equals "true" and "0" equals "false".

Accepts a single parameter. 

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