Where can I get life orbs?

Hello there, I'm curious about something. I've heard about these "life orbs" and I'm wondering, where can I actually acquire them? Are they something that can be purchased online? Or do I need to go to a specific store or location to get my hands on them? I'm really intrigued by the concept and would love to learn more about how to obtain them. Thanks in advance for any information you can provide!