Lolita is generally a very cutesy style, and people within this subculture usually wear victorian style dresses. The only real difference between each Lolita styles are the colors they wear, and the accessories they choose.
The most recognizable style is sweet Lolita. This type of Lolita is marked with very bright pastel colors, usually pink. The wearer generally dresses very doll like, with bouncy dresses and big bows. Cute accessories like stuffed animals and purses are often used.
Wearers are inspired from Victorian Goth styles, and wear muted black and grey colors. Lacy black stocking and gloves are there accessories of choice as well as black cross necklaces. Dresses and undershirts are often decorated with ruffles and lace.
This is the male version of Lolita and is inspired by male victorian clothing. Males usually wear shorts that cut off at the knee called "prince pants" and blouses with a vest on top. They also often wear top hats and knee socks or stockings and accessorize with pocket squares and pocket watches.
This style is closely related to common western style. This is a very glitzy glam style where women often tan themselves, dye there hair blonde (or bye wigs) and wear very western style clothes. Makeup is often over exaggerated with fake eyelashes and thick black eyeliner and thick foundation. Girls often wear clothing that reveals lots of leg, and accessorize with designer handbags and jewelry.
Kogal could be considered to be more like cosplaying to westerners. This fashion is all about dressing up in Japanese school girl uniforms, mainly high school uniforms. Unlike normal high school uniforms, girls wear shorter skirts, loose socks and dye their hair. This style isn't really that popular anymore, so you probably won't see it much besides cosplay.
The clothes in this style would be classified as "normal" but what really makes the decora style is the huge amount of accessories they pile on (decor). Hair is adorned with tons of colorful cute hair clips, and arms and legs are layered with stockings, leg-warmers, arm-warmers and socks. People also dye there hair bright pastel and neon colors.
These are only a few styles that are popular in Japan, there are plenty more that can't be discussed in one article. In a future article I will discussing more Japanese sub-culture and styles that you could incorporate into your daily wardrobe, happy shopping!