Summarize the following:
A vivarium is a wooden tank with a glass front, which will help to keep your electricity bills down. Leopard geckos are ground animals, so they will rarely climb, but you should use a glass tank so the leopard cannot climb up the walls of the tank. You should not use a wire or mesh cage for your gecko, as wire cages will not hold heat very well, are easy for your gecko to escape from, and your gecko can get injured if his foot or toe gets caught in the wire. Leopard geckos are not very active lizards, but they should be given a good amount of room to move around. However, avoid getting a tank that is too large for young geckos, as a tank that is too large can make it difficult for your gecko to find the heat source in the tank and hide. Adults have no size limit, but larger tanks must include plenty of hides. The recommended sizes are 20 gallons (75.7 L) for one adult leopard gecko and 10 gallons (37.9 L) for one baby leopard gecko.  A single adult Leopard gecko will need a 10 gallon tank (20 gallons would be better), two geckos will need a 15–20 gallon (56.8–75.7 L) tank and three geckos will need a 20–30 gallon (75.7–114 L) tank. Up to three Leopard geckos can be kept in the same cage, though they should be of a similar size and males should be kept alone. Only females who are similar in size can be housed together, and even then they may fight. Keep an extra tank incase they fight.

Summary:
Use a long and wide aquarium, terrarium, or vivarium. Provide your gecko with plenty of space.