The at sign, @, is normally read aloud as "at"; it is also commonly called the at symbol, commercial at, or address sign.

The earliest yet discovered symbol in this shape is found in a Bulgarian translation of a Greek chronicle written by Constantinos Manasses in 1345. Held today in the Vatican Apostolic Library, it features the @ symbol in place of the capital letter alpha "Α" as an initial in the word Amen; however, the reason behind it being used in this context is still unknown.

A common contemporary use of @ is in email addresses.

In Afrikaans, it is called aapstert, meaning 'monkey tail'; in Armenian, it is շնիկ (shnik), which means 'puppy'; in Belarusian, it is called сьлімак (sʹlimak, meaning 'helix' or 'snail'); in Kazakh, it is officially called айқұлақ (aıqulaq, 'moon's ear'); in Norwegian it is often called "grisehale" (pig's tail).

More Info: en.wikipedia.org