There's no real, scientifically accepted difference between a mushroom and a toadstool, and the terms can sometimes be used interchangeably to refer to the same types of fungus. However, in common, non-scientific usage, the term “toadstool” is more often given to those fungi that are poisonous or otherwise inedible.
Some good rules apply for avoiding poisonous mushrooms if you are a novice;
- Avoid mushrooms with white gills, a skirt or ring on the stem and a bulbous or sack like base called a volva. ...
- Avoid mushrooms with red on the cap or stem. ...
- Finally don't consume any mushrooms unless you are 100% sure of what they are.