How do you teach kids to understand death without scaring them?

I've had a tough time talking to my kids about death in a way that's honest but not terrifying for them. As their parent, I want to prepare them for reality but I also don't want them to think about it all the time. My youngest just found out about the permanence of death after grandma passed away, and I'm not sure how much to reveal.

I've noticed that kids seem to understand the concept of 'not waking up' or 'moving on' to their next life, but they can get really stuck on 'what happens after that.'

Has anyone else out there struggled to balance their kid's curiosity with the harsh reality of death, or have tips on how to tackle this in an age-appropriate way?