"Steroid" is the name given to a chemical compound with a specific structure. In everyday speech, the term steroid is applied to several medications that share this structure; however, these medications have very different uses. Anabolic steroids are a class of drug that mimic the effects of male sex hormones called androgens which stimulate muscle growth and secondary male sex characteristics. They are often abused by bodybuilders and other athletes to build muscle mass and so should be used with caution. When prescribed, oral steroids should be taken as directed. If you come across extra pills that haven't been taken, and are unsure if they are steroids, you can identify the pill based on its physical appearance, information on the bottle, or by consulting a professional.
DHT is the testosterone metabolite which is primarily active in tissues other than skeletal muscle. It is 100x stronger than testosterone, but found in far less concentration. It would follow that DHT is the active metabolite of testosterone acting on adipose tissue, skin etc, or any tissue rich in 5-alpha reductase. DHT has the ability to competitively inhibit the activity of estrogen in the tissues where it predominates over testosterone, adipose tissue being one of them. The lessened tissue-specific binding ability of estrogen due to the elevated presence of DHT would limit estrogens tendency to promote the volumization of adipocytes, thus leading to a preferable fat burning environment as a result of DHT or DHT derived drugs such as var and win.