The bigint data type in JavaScript is used to represent very large integers that cannot be handled by the standard number data type.
It's worth noting that bigint is a relatively new feature in JavaScript, introduced in ES2020, and may not be supported by older browsers.
A bigint value is represented by adding an "n" at the end of the number. For example, it can be declared as follows:
let bigInt = 123456789012345678901234567890n;
The bigint type can be calculated in the same way as the number type, but a conversion is required for calculations involving the bigint and nunber types.
let x = 12n; // bigint
let y = 15; // number
console.log(x + BigInt(y));