There are two main categories of injectable wrinkle treatments. One works by relaxing the muscles that are causing the wrinkles. Doctors call this category neuro-modulators. It includes Botox and Dysport, the only two approved for treating wrinkles in the United States. There are others available in other countries, and there are also others on the horizon.
The second category of injectable wrinkle treatments is fillers. Some fillers are permanent like silicone and Artefill. Others are temporary and work either by taking up space or by promoting collagen production or both. The hyaluronic acid fillers including the Juvederm family and the Restylane family are the most popular. They have the advantage of working immediately, lasting a long time, and are natural skin products. They can also be dissolved easily if there is an area that you don't like.
These kinds of treatments are very popular because they are easy, affordable, and make you look really great. There are new products introduced all the time, and it can be confusing to sort out the differences. It is best to talk to your cosmetic surgeon and get advice for what is best for you.