Cactus are succulents that grow in the soil and need a lot of water to survive. They thrive on heat and light. If you want to take care of your cactus, use these tips from David Gledhill from green-thumb.com
1) Only give them what they need: Don't over-water or over-light your indoor cactus because this can cause root rot. Keep the soil moist but not soggy.
2) Provide a saucer or dish under the plant: The plant needs to have a saucer or dish that is filled with water to allow excess moisture to escape, so it doesn't pool around its base and cause root rot.
3) Make sure the plant has good drainage: Use pebbles or perlite to help.