Difference between Shimano HG and XT cassettes I'm looking to build a 1x10 commuter bike.

Want to decide between these two cassettes

XT series: 

http://a.co/d4ez069

HG series:
http://a.co/j4z8KFn

How do they differ?

I still haven't bought chain and crankset.
XT is shimano's MTB line - and its second below the XTR line.  It weighs a claimed 275 grams, and can be split in the middle to remove a medium cog and add a larger one on the end.

HG is also a MTB line, but ranks somewhere below XT.  It weighs more at around 430 grams, and therefore is more solid.  It cannot be tweaked, but will be more robust and less prone to breaking.

In 2016, the Shimano MTB group lineup is something like this:

Lowest TOURNEY, ALTUS, Acera, ALIVIO, Deore, Deore LX, Deore XT, XTR Highest

By comparison, the road groups are

Lowest A050, Tourney, Claris, SORA, TIAGRA, 105, Ultegra, DURAACE, Highest

A further breakdown can be found at http://productinfo.shimano.com/#/lc/1.7



To clarify - here's shimano's current line up, according to shimano, from the link above, which is dated 2016 and titled "Product lineup"  



Note this is from the PDF linked from that page.

Answer My advice would be to get the cheaper heavier cassette and a new chain at the same time.   They are wear items, and should be replaced periodically.  Some indication that the light one was perhaps too light for the amount of power some riders were generating.