Modern Full-Stack Development

“express” : “1.2.3” – NPM will grab this specific version only.
• 
“express”: “~1.2.3” – NPM will grab the most recent patch version. 
(So, ~1.2.3 will find the latest 1.2.x version but not 1.3.x or anything 
below 1.2.x.)
• 
“express”: “^1.2.3” – NPM will grab the most recent minor version. 
(So, ^1.2.3 will find the latest 1.x.x version but not 1.3.x or anything 
below 1.x.x.)
• 
“express”: “*” – NPM will grab the newest version available. (There is 
also an explicit latest value that does the same thing.)
There’s quite a lot more to SemVer than this (and there’s also no shortage of criticism 
and folks who aren’t exactly fans of it), but this should cover the most common features 
you’re likely to encounter. Indeed, this should be all you will need for this book.
Note  When using the npm install
 command, you can add  
@major.minor.patch after the package name to specify the version to install 
using all the Semver rules described in the preceding text.