Feta is an ancient cheese made in Greece and nearby countries. It is a white, crumbly cheese with a salty flavor. Feta outside the European Union is usually made with cow's milk, but in Greece it is made from sheep's milk. Goat's milk can be added, as long as it is no more than 30% of the mixture.
The Countries of Greece and Denmark had a long legal battle over the name Feta. Greece wanted the name protected, Denmark did not, since they made a cheese with the same name from cow's milk. Initially Denmark won as the courts ruled that Feta's true origins have been lost to history. Finally in 2005 the name Feta received PDO status in the European Union. Denmark's Feta was renamed Apetina.
Feta cheese is very ancient, but it's name is not. The Greek poet Homer described the Cyclops making Feta cheese. And Feta cheese was very likely to have been around much longer than Homer, it's origins being lost in antiquity. The name however, is from the 17th century. Feta means "slice", perhaps coming from how Feta cheese was often sliced to be placed in barrels.
There are many cheeses similar to Feta. And outside of Europe, there are many cheeses named Feta. Feta outside of Europe is often saltier than traditional Feta from Greece.
Fetamania is a website about Feta.
Some information found on this page also came from the book Cheese by Juliet Harbutt.
Where to buy
In North America many grocery stores sell Feta cheese, but much of it is produced outside of Greece.
amazon.com sells Feta cheese, both authentic Greek Feta, and some other varieties.