Death is such a common thing and it's so simple that websites like this one violates Occam's Razor in explaining what actually happens after death. In a way, I do too, but only because I extremely extrapolate reality. I really don't believe anything on that website. Christian propaganda.
Not clicking that link, but based on title? "Death" isn't understood as some final end in this one's traditions for a variety of reasons, and while it's a bit of an oversimplification to say it's a transition into a "spirit world" it's not terribly far off from a certain point of view.