What does @ prefix in package.json dependecy path means

As my understanding earlier was that we could refer dependencies,

1. directly 'some-dep-from-global' or
2. github 'git+ssh:something#v1.1.1'or
3. local '~/something' etc

But came across node project which has dependencies listed using prefixed "@somename/" which I have not come across till now. I am trying to run project but '@something/**' dependencies are not getting installed.

What exactly it is? Is it another way of configuring dependencies locally? Any inputs would be helpful.

"dependencies": {
    "@somename/some-dep-1": "^1.1.0",
    "@somename/some-dep-2": "^1.7.0",
    "@somename/some-dep-3": "^1.0.4"
}

via Anil Namde