An encyclopedia is a reference work often in several volumes in which articles on various topics can be found. It is often arranged in alphabetical order.
The Encyclopedia Brittanica is offered in 32 volumes. This is the most complete encyclopedia one can ever find but its price is very expensive. In fact, you have to pay $1,395.00 USD to get the whole Encyclopedia Britannica. However, other books such as the Concise Encyclopedia and other DVD-Rom or CD-Rom like the Encyclopedia Britannica Ultimate are more affordable. They are sold at a price of $60 USD.
Britannica children's encyclopedia include My First Britannica, Britannica Student Encyclopedia, Britannica Discover America, Britannica World Atlas and many more.
The encyclopedia Britannica is also offered online. It is possible to use for free the concise Encyclopedia, the Merriam Webster dictionary, a Thesaurus, etc. You can also have the opportunity to sign up in order to receive premium member services.
As for Encarta encyclopedia, it is completely free and you can find anything on any subjects.
Finally, if flowers are one of your hobbies, it is always good to know that there exist free flower encyclopedia over the Internet. That way, you will know everything that has to be known on each species of flowers.