What is the difference between Hitachi and HGST?

I understand HGST has been acquired by Western Digital but I've yet to understand the difference between Hitachi drives and HGST drives. Is the underlying technology the same and everything is just branding? I haven't had good experiences with Hitachi drives since they all come with laptops and those drives fail within 2 years.

HGST is the new name for Hitachi after they bought IBM's HDD arm

Funny. All the laptop OEM drives i've encountered still bear the Hitachi name instead of HGST. They're never reliable since they all failed shy of 2 years. The reliability reports on most sites state HGST is the most reliable, hence my confusion.

Using a hitachi drive as my only drive. Came out of an HP. May it never die.

Have a HGST 500g 2.5inch 7200rpm too. Would like to use for a itx build.

Branding but hgst has better QA.

That would line up with my anecdotal experiences.

How many years has that drive been running? I recently received a few laptops to fix, I extracted the dead drives and all of them were 2.5' drives. That makes me kind of want to avoid 2.5' drives in general. I just so happen to encounter more Hitachi drives than WD drives, since they're bundled with it. It also doesn't help that my old laptop from Samsung requires 7mm 2.5' drives.

Hitachi is 3.5, up time probably 5 years. (sleep mode and off, etc)

The 2.5 is plugged in but I do not use it for anything. Should do a linux or something (probably won't).

i have an HGST drive, and yes it comes up as "hitachi" when i check the device properties.

Yup as above, Hitachi's HDD end was bought by Western Digital after the floods a few years back and it was rebranded HGST.

But at the same time there was a significant change in the QA of the drive and a shift from mostly consumer cheap drives to better consumer drives and enterprise drives. The old Hitachi Deskstars used to be known as Deathstara duentho their terrible reliability, now look they are the best out there.

The 2.5" in my Dell E5530 has held up pretty nicely. I think it may be failing though as I can't write a partition table for a Linux install (well I can, but after I do, the partition table is messed up, and the names date back to mid March when I installed LMDE 2 making a dual boot impossible).