Simply
==
means comparison between operands with type conversion
&
===
means comparison between operands without type conversion
Type conversion in javaScript means javaScript automatically convert any other data types to string data types.
For example:
123=='123' //will return true, because JS convert integer 123 to string '123'
//as we used '==' operator
123==='123' //will return false, because JS do not convert integer 123 to string
//'123' as we used '===' operator