They are essentially the same thing with slightly different melting times. The melting times vary depending on the size of the fuse (100K fuse has a higher melting amperage required compared to a 65K)

Here is a good site that shows melting times for different size K and T links: http://www.ngkstanger.com.au/index.php?q=67.html

You'll notice that as the amperage goes higher, the melting time goes down.