Help required with Equals keyword

I am not able to understand what Equals does in this context. Is it a keyword or a type? I am not able to find documentation for it.

Lines 19 to 21 in 9fada03

    
           type StringEqualCondition struct { 
        
           	Equals string `json:"equals"` 
        
           }

Sorry, misunderstanding on my part

	type StringEqualCondition struct {
	Equals string `json:"equals"`
	}