Only

major

version will stick to

1

but

minor

and

patch

will be the latest versions

"dependencies": {
    "moment": "^1.6.2"
}

Only updates

patch

but

major

and

minor

will be the specified versions

"dependencies": {
    "moment": "~1.6.2"
}

Exactly the specified version

1.6.2

will be installed

"dependencies": {
    "moment": "1.6.2"
}

The latest version of the package will be installed

"dependencies": {
    "moment": "*"
}