Lolita fashion is a street fashion style originating in Japan. It is one of the most popular Japanese street fashion styles and has also become quite popular in the Western world, as well, thanks to Otakus, weeaboos, and other westerners with a fascination for Japanese pop culture. Contrary to popular belief it has nothing to do with the book or movie, Lolita.
It is a (mainly) a dress style that is inspired by the styles of the Rococo, Victorian, and Edwardian eras and involves (most of the time) curls, big bows, frilly petticoats, bloomers, ruffly blouses and the like. The term is actually an umbrella term with many sub-cultures including:
Sweet Lolita-bright colors, very girly, usually with a cute theme like candy, cartoons or fairy tales. The main goal of this look is to be as cute as you can!
Gothic Lolita-dark colors, but not really like western goths. Think Wednesday Addams, only cuter!
Classic Lolita-Neutral colors, somewhere in between first two, but more mature and modest. Often uses more traditional-looking Victorian clothing and longer skrits.
Punk Lolita- combines the look with classic punk style elements like chains, spikes, pleaded plaid skrits, and combat boots.
Country Lolita- Think Anne of Green Gables or Dorothy from The Wizard of Oz. Cute, but modest. Lots of gingham and fruit prints, usually has a straw hat or a picnic basket as the main accessory.
Kuro Lolita- All-black clothing
Shiro Lolita- Like "Kuro" except all-white
Mono Lolita- Just black and white
Pinku Lolita- All-pink
Mizurio Lolita- All-Blue
Aka Lolita- All-Red
Hime Lolita- Princess/Royalty themed, borrows heavily from Rococo. Very elegant and elaborate, often includes crowns, big hair, pearls, and scepters
Sailor Lolita- based on sailor suits and includes nautical related-accessories like anchors and life-perservers.
Wa Lolita- based on traditional Japanese clothing such as kimonos.
Qi Lolita- based on traditional Chinese clothing such as qipao (Cheongsam)
Ero Lolita- Short for erotic, less modest than the other sub-cultures/styles, involves a lot of sexy stuff like bare corsets and shorter skirts.
Guro Lolita- combines it with blood, gore, injury, mutilation and other gross stuff.
Casual Lolita-Simple, Non-Lolita items (headband, t-shirts, no wig, regular shoes) mixed with Lolita stuff. Often done by newcomers to the subculture or those who don't have much money or time.
Steampunk Lolita- incorporates steampunk elements, like goggles, clocks gears, and primative gadgets.
Pirate Lolita- incorporates pirate elements like swords, eyepatches, skulls treasure chests, etc.
Military Lolita- incorporates military/army uniform elements.
Cosplay Lolita- a Lolita outfit worn as a costume or cosplay.