The word "edible" describes anything that you can eat. But it's now a term that's popularly used for foods, often treats, that have extracts from marijuana or other mind-altering drugs in them. Marijuana includes the leaves, flowers, stems, and seeds of related plants also known as cannabis. The active ingredient is a chemical called THC.
Edibles are better for your lungs than smoking.
But it's a good idea to take precautions with edibles, too, especially if you are new to them.