BigInt is an arbitrarily long integer. Numbers in JavaScript are stored as 64-bit, floating-point doubles. This means that even if we only have a normal integer, we still only get 53 bits of precision. We can only store numbers inside variables up to the number 9 quadrillion. Anything bigger than this will usually cause the system to go into undefined behavior. To make up for this, we can now utilize the BigInt feature in JavaScript. This looks like the following:

const bigInt = 100n;
console.log('adding two big ints', 100n + 250n);
console.log('add a big int and a regular number', 100n + BigInt(250));

We will notice that BigInts are appended with an n. We also need to coerce regular numbers to BigInts if we want to utilize them in regular operations. Now that we have big integers, we can work with very large numbers, which can be of great use in 3D, financial, and scientific applications.