Here is a list of some of the common words, terms and definitions in the field of terrariums.

Terrarium: A small container or enclosure, usually glass, that contains a variety of small plants and sometimes animals. Typically it is created in a way that makes it a small representation of an eco-system. Sometimes a terrarium also includes small animals or reptiles.

Vivarium: A small container or enclosure that houses small animals or reptiles. It can contain water effects, plants and other life but the overall goal of the vivarium is to make a habitat for some kind of living animal or reptile.

Wardian Case: A type of glass terrarium. Usually they are made of some type of iron or metal framework that holds sheets of glass. They are named after the inventor Nathaniel Bagshaw Ward. Who made them in victorian England to house and ship various types of plants. I have more about Ward and Wardian cases here: The History of the Wardian Case

Activated Charcoal: This is a form of charcoal that is used to purify water. It is most often seen in aquariums where water is pumped through a container with activated charcoal. The charcoal absorbs all the impurities. It is sometimes used in terrariums but is not mandatory. Terrariums will often do quite well without it. If the terrarium or vivarium has animals or reptiles it is better to have the charcoal so as to purify the water. You can buy activated charcoal at any pet store that sells aquarium supplies.

Here is a sample on amazon.com: Marineland Black Diamond Activated Carbon 40 oz

arium - this is the latin for closed container.

Closed terrarium: This is a terrarium that is totally enclosed, usually a glass container with a lid or a cork. The closed system rarely needs any type of watering or other care, just sunlight. The water recycles itself through evaporation. A closed system can survive healthily for years if the percentage of water content is balanced.

Open terrarium: Often called a dish terrarium or pot garden. It is some kind of container that is opened to the air around it. It can be easier to maintain than a closed terrarium but will need regular watering.

Paludarium: A type of terrarium that has a strong water content which can include an underwater section. Often they simulate a rain forest or a swampland and typically it houses some kind of animal life either on land or in the water. I have more about Paludariums here

Bottle Terrariuim: A closed system terrarium that is housed specifically in some kind of glass or plastic bottle. This is a common project for school kids who use two liter soda bottles. I have a tutorial on making one of these right here: Bottle Terrarium

eco-system: The term for a complete self sustaining living system. This can vary quite a bit but in terms of terrariums it usually includes soil, a variety of plants, water, and some type of animal life. The point in a terrarium is to have the eco-system be fully sustainable on its own without any outside influence except for sunlight.

Spaghnum Moss or Spanish Moss: This is often used in terrariums as a barrier between the soil and the stones. It prevents the soil from running down into the stones causing a muddy mess! You can susbstitute this for other types of organic materials.

Premium Kit for Small Terrarium (Succulent, Cactus, and Fairy Garden)

Perfect kit for a first time terrarium gardener or to give as a gift. Provides the exact amount of the specific "ingredients" necessary to build a thriving small terrarium. Will work for closed terrariums, open terrariums, fairy gardens, as well as with succulents and cactii. Kit includes terrarium potting soil, activated charcoal, two different sizes of semi-polished river rocks, shag moss, and complete but easy to follow step-by-step instructions. The ingredients supplied are in the following approximate amounts: 9 oz. soil; 8 oz. small river rocks; 8 oz. larger river rocks; 1 oz. activated charcoal; 1 oz. sheet moss. Great for anyone wanting to set up a terrarium without having to go and find all the different pieces separately. Please note that the kit does NOT include a container or plants. Please also note that this kit is for a SMALL terrarium. We recommend using a mason jar if you are making a closed terrarium or a container with a 4 - 6" diameter if you are making a succulent or cactus terrarium.