Web3 is a collection of libraries that allows you to read and write to the Ethereum blockchain.
It allows you to send Ether from one account to another, get balance of an account, create smart contracts, read and write from smart contracts among other things.
Web3.js connects with ethereum node (for example your node in DEPLOY) with JSON RPC (Remote Procedure Call) to read and write data to the network.
The web3.js library is a collection of modules which contain specific functionality for the ethereum ecosystem.
web3-eth is for the ethereum blockchain and smart contracts
web3-shh is for the whisper protocol to communicate p2p and broadcast
web3-bzz is for the swarm protocol, the decentralized file storage
web3-utils contains useful helper functions for Dapp developers.
Node.js can be use to create web-servers and networked applications.
Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
Node Package Manager (npm) which is package manager that makes installing Node packages fast and easy.
NPM gets installed when you install NodeJS.
brew install node
Download latest version and go through installation process.
brew uninstall node
You can now use NPM to install Web3.js library through the terminal.
npm install web3