However, in reality you should really just concatenate, compress and use one file.
For the purposes of development I tend to rely
@import for the simple ease of being able to break CSS into smaller component files so that it’s just that much easier to work with and bug test. For production you’re much better off combining them into a single CSS file.
As georgearnall mentioned though; if you ARE going to use one of these in a live site the preferred method is
<link> because it allows for multiple HTTP requests to be made whereas the
@import method does not.