// Array :- It is collection more the single value inside an variable // concat :- It return a new array by merging two or more than two arrays. // e.g. Merging more than two arrays const lang1 = ["python","java"]; const lang2 = ["c++","javascript","react"]; const lang3 = ["English" ,"Sanskrit","Marathi"]; const output =lang1.concat(lang2 , lang3);//here we have to add the arrays that want to get merged console.log(output);//It only create new array and not change the original arrays console.log(lang1);//not change like me console.log(lang2);//as it is console.log(lang3);//as it is