Dotenv: .env is zero dependency module that loads enviorment variables from a .env file into process.env .
ex- const key = process.env.secretkey
this secretkey is declared in our .env file and that file will not be public.
Bcrypt: Bcrypt is a library that help you easily hash password and compare them in node.js
UUID: UUID is a unique random number ids values generator . It generate string random values.
Axios Axios is a popular promise based HTTP client for the browser and node.js .
Socket.io : Socket.io enables real time bi-directional communication between web clients and servers.