What "worm castings" means in gardening

Worm castings, also known as vermicast or worm manure, are the excrement of earthworms. They are rich in nutrients, minerals, and beneficial microorganisms, making them an excellent organic fertilizer and soil conditioner. Worm castings are odorless, non-toxic, and safe to handle, and they can be used for all kinds of plants, vegetables, and fruit trees, both indoors and outdoors. They improve soil structure, water retention, and aeration, boost plant growth and productivity, and suppress plant diseases and pests.