====== Install npm packages locally vs globally ======

When managing dependencies in a Node.js project, you often have a choice between installing packages **globally** and installing them **locally** within a project. Both approaches have their use cases and advantages, and **you can run local packages using npx** without installing them globally.

===== Global installation =====

Global installation installs a package in a central location on your system, making it accessible from any directory. This is often used for command-line tools that you want to use across multiple projects. \\ 

**Command to install globally**: 
<code>
npm install -g <package-name>
</code>
**Command to run it**: 
<code>
<package_name>
</code>
**Use case**: Useful for CLI tools that you want to use across different projects. \\ 
**Access**: You can run the command from anywhere in your system. \\ 
**Versioning**: One version installed for all projects, which can lead to version conflicts if different projects require different versions. \\ 

===== Local installation =====

**npx** is a command-line tool that comes with npm (version 5.2.0 and higher) that allows you to run locally installed packages as if they were installed globally. \\ 

**Command install locally**: 
<code>
npm install <package_name>
</code>
**Command to run with npx**: 
<code>
npx <package_name>
</code>
**Use case**: Ideal for project-specific dependencies or when you want to try a package without installing it. \\ 
**Access**: You can only run the command within the project where it's installed or explicitly specify the package with npx. \\ 
**Versioning**: Each project can have its own version of the package, reducing conflicts. \\ 

===== Comparison =====

  - **Flexibility**: **Local** installation with npx offers more flexibility, as you can have different versions for different projects.
  - **Ease of use**: **Global** installation is easier to use across multiple projects but might lead to version conflicts.
  - **Isolation**: Using npx with **local** packages ensures that your project’s dependencies are isolated from other projects, leading to more predictable behavior.

===== Example =====

Suppose you want to use terser to minify files:

==== Global Installation ====

Install:
<code>
npm install -g terser 
</code>
and then run:
<code>
terser file.js -o file.min.js
</code>

==== Local Installation ====

Install:
<code>
npm install terser 
</code>
and then run within the project where terser is installed:
<code>
npx terser file.js -o file.min.js
</code>