These are the basic Karate Stances. This is from Shotokan Karate style but this applies to other styles too.
Shizentai – Natural Stance
Heisoku-dachi (閉足立, Feet together stance)
Feet together. This is usually a transitional stance, although it is used as the ready stance in some kata.
From musubi-dachi, open heels until both outer edges of feet are parallel. Some styles don't distinguish this stance from heiko-dachi.
Hachiji-dachi (八字立, natural stance, literally "stand like the character 八")
The feet are shoulder width apart, toes open at 45 degrees. Sometimes this stance is called soto-hachiji-dachi (外八字立). This is the basic ready stance in Karate.
Renoji-dachi (レの字立, stand like the character レ)
Feet are at the shoulder width. The foot in the front is fully frontal (toes facing forward), the rear foot is turned 90 degrees out, and is positioned in such a way that if the front foot is brought back, its heel will touch the heel of the rear foot. Thus the foot print is shaped like the character レ (or letter L). The weight is kept 70% on the rear foot.
Zenkutsu-dachi (前屈立, forward stance)
This is a long frontal stance where the weight is mostly on the front leg. It has exactly the same height as shiko-dachi, but the rear leg is completely straight at the knee and extended back. The front foot is placed frontal (toes facing forward), the rear foot is turned out 30 degrees, just like Moto-dachi, but never 90 degrees as seems natural to new practitioners because this precludes any forward motion. The heel of the rear foot rests on the ground. Zenkutsu-dachi is one of the most common stances in kata.
Kōkutsu-dachi (後屈立, back long stance)
This is a mirror image of zenkutsu-dachi, where the rear leg is bent strongly at the knee and the front leg is either straight or slightly bent, depending on the style. The rear foot is turned 90 degrees to the side. The body is turned 90 degrees or more away, except for the head which looks to the front. Kokutsu-dachi is a great defensive stance because of the amount of energy stored in the rear leg, ready for a counter-attack.
Kiba-dachi (騎馬立, horse stance or rider stance)
Feet are parallel and wide, weight is central and low, with the back straight and the knees and feet pointing slightly inwards. This stance is not used in all styles of karate because of strong tension that it requires, instead it is often replaced by Shiko-dachi.