Double equals (==) is abstract equality comparison operator, which transforms the operands to the same type before making the comparison.
For example,
5 == 5 //true '5' == 5 //true 5 == '5' //true 0 == false //true
Triple equals (===) are strict equality comparison operator, which returns false for different types and different content.
For example,
5 === 5 // true
5 === '5' // false
var v1 = {'value':'key'};
var v2 = {'value': 'key'};
v1 === v2 //false