[pluma]

Definitely a regional thing. In Germany both terms appear as loanwords (I don't think there is a "real" German word for it) and they're used interchangeably.

One of the two was a trademark leading to the other one being pushed as an alternative. But I can't even remember which one -- at this point I couldn't even tell you which phrase is more widely used.

EDIT: IIRC at some point "Notebook" was used to refer to laptops that were smaller and/or lighter than the regular (rather heavy and bulky) laptops at the time. There's also a major online discounter called notebooksbilliger.de (literally "cheaper notebooks"). In day to day language I would err towards "Laptop" being the more widespread term but not by much.

[patrickg]

I like the German word "Klapprechner" (something like "foldable computer").

[martin-adams]

You're not referring to netbooks are you?

[pluma]

No, netbooks were a separate category in sizes that are now common with tablets (i.e. around 10 inches). There's also "subnotebook" but I never understood the exact distinction of that category.