Map :

map is an array method .
Map filter reduce map method does'nt change the original array. Map will take each item and modify and return modified one . if we sent 10 items . it will give 10 modified items back . it will push into new array

Filter :

THe functionality of filter method is that based on its function argument returns value
if the return value is true then it place in a new array else it does't
Place the item where condition returned true in a array
ex : var ar =[12,10,23,22,15,51,89,34];
var x= ar.filter(function(a){
if (a%2 ===0){
return true
}
else{
return false
}
}) console.log(x)

Reducer :

If we sent 10 item it will give single Entity or Only one