UrlPathEncode vs. UrlEncode

What is the difference between

HttpUtility.UrlPathEncode(params);

AND

HttpUtility.UrlEncode(params);

I looked at the MSDN pages
https://msdn.microsoft.com/en-us/library/system.web.httputility.urlpathencode(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.web.httputility.urlencode(v=vs.110).aspx

but it only tells you not to use UrlPathEncode, it doesn't tell what the difference is.