What is the difference between ’global’ and ’local’ installations of npm packages?

The difference between ‘global‘ and ‘local‘ installations of npm packages lies in the scope and the purpose of the installation.

A ‘local‘ installation is specific to a particular project, and the packages are installed inside the ‘node_modules‘ directory of your project folder. This means the package can only be used within the specific project, making it a good choice when you need certain functionality for that particular project. Local installations also allow for better project isolation since each project maintains its dependencies separately, thus avoiding potential clashes or conflicts with other projects.

To install an npm package locally, you simply run:

npm install package-name

A ‘global‘ installation, on the other hand, makes the packages available to your entire system. That means you can use them in any project on your machine. Global installations are typically used for installing command-line utilities, development tools, or other packages that are not tied to a specific project but are helpful across multiple projects. Global packages are installed in a system-wide directory, which varies depending on your operating system and npm configuration.

To install an npm package globally, you run:

npm install -g package-name

Here’s a summary of the differences between global and local installations:

1. **Scope:** Global installations are system-wide, whereas local installations are project-specific.

2. **Directory:** Global packages are installed in a system-wide directory, while local packages are installed in the ‘node_modules‘ folder of the project directory.

3. **Usage:** Global packages are usually made for command-line utilities or development tools that can be used across multiple projects. Local packages are used in a project to provide additional functionality or utility.

4. **Isolation:** Local installations provide better project isolation since dependencies are managed separately for each project, avoiding potential version conflicts.

In most cases, when you’re working on a project, you’ll want to use local installations to manage your project-specific dependencies. However, when you need a tool or utility that is helpful across multiple projects, a global installation is the way to go.