What is Leca and why is it useful for plants?

Leca is an acronym and it stands for: Lightweight expanded clay aggregate. It sounds very complicated, but it's quite easy to explain. Essentially, Leca is a growing medium, like soil, in which you can grow your plants. Leca is a collection of baked clay balls that expand when you soak them in water.

This is a companion discussion topic for the original entry at https://plantcareforbeginners.com/articles/what-is-leca-why-useful-for-growing-plants

Leca really is that magical thing that has saved so many of my plants and helps to keep them strong and healthy! Have you tried it yet? What are your experiences? :herb: