This blog is amazing. Nice article 👍👍. A lot of useful information. Now, Hash table concept is clear 👏👏 I have a question that where we use hash tables. Mostly till today, I used objects and arrays in frontend and as well as in the apis. But never used Hash tables. I think Hash tables may be used in cryptography or where security is important. Is there any other usecase in common scenario such as in e-commerce website?