Node.js has a set of core modules that are part of the platform and come with the Node.js installation.

We have a lot of them:

Name	Description
assert	provides a set of assertion functions useful for testing
buffer	provides the ability to handle buffers containing binary data
child_process	provides the ability to spawn child processes
console	provides a simple debugging console
cluster	allows to split a Node.js process into multiple workers to take advantage of multi-core systems
crypto	provides cryptographic functionality
dgram	provides an implementation of UDP Datagram sockets
dns	provides name resolution and DNS lookups
events	provides an API for managing events
fs	provides an API for interacting with the file system
http	provides an HTTP client/server implementation
http2	provides an HTTP/2 client/server implementation
https	provides an HTTPS client/server implementation
net	provides an asynchronous network API
os	provides operating system-related utility methods and properties
path	provides utilities for working with file and directory paths
perf_hooks	to enable the collection of performance metrics
process	provides information about, and control over, the current Node.js process
querystring	provides utilities for parsing and formatting URL query strings
readline	provides an interface for reading data from a Readable stream
repl	provides a Read-Eval-Print-Loop (REPL) implementation that is available both as a standalone program or includible in other applications
stream	an abstract interface for working with streaming data
string_decoder	provides an API for decoding Buffer objects into strings
timers	provide functions to schedule functions to be called at some future period of time
tls	provides an implementation of the Transport Layer Security (TLS) and Secure Socket Layer (SSL) protocols
tty	provides functionality used to perform I/O operations in a text terminal
url	provides utilities for URL resolution and parsing
util	supports the needs of Node.js internal APIs, useful for application and module developers as well
v8	exposes APIs that are specific to the version of V8 built into the Node.js binary
vm	enables compiling and running code within V8 Virtual Machine contexts
wasi	provides an implementation of the WebAssembly System Interface specification
worker	enables the use of threads that execute JavaScript in parallel
zlib	provides compression functionality

Check out my detailed tutorials on

• The Node.js events module
• The Node.js fs module
• The Node.js http module
• The Node.js os module
• The Node.js path module