pnpm is also known as performent npm. It is a new package manger which can be used instead of npm or yarn. It is basically a drop-in replacement for npm, which means that once you install it, you can invoke pnpm install to download a project dependencies, and all will work transparently for you.

What differentiates pnpm is the way packages are managed. npm and Yarn install separate copies of the packages in every project, on the other hand, pnpm keeps a single copy of every package and uses hard links/symlinks to reference the original installation. So:

• if you depend on different versions of the dependency, only the files that differ are added to the store. For instance, if it has 100 files, and a new version has a change in only one of those files, pnpm update will only add 1 new file to the store, instead of cloning the entire dependency just for the singular change.
• All the files are saved in a single place on the disk. When packages are installed, their files are hard-linked from that single place, consuming no additional disk space. This allows you to share dependencies of the same version across projects.

real-world example:

**npm:**
Project Size: 1.5 GB

**pnpm:**
Project Size: 228 MB //reduce the space up to 85%

The above illustration has been tested in my real project.

all in all, you save a lot of space on your disk, and your installations would be twice faster than other package managers!

Installation: click here for more information about installation