Many products in our everyday life are tested on animals. This testing involves cruelty to the animals who are imprisoned, exploited, and eventually killed. Skin-care products and makeup do not need testing since they can be made with safe ingredients.
A vegan lifestyle avoids using animal-based materials in apparel such as fur, leather, wool, down, and silk. Using animals to get these requires they be imprisoned, exploited and even killed. Fashion does not ever need to inflict cruelty onto other sentient beings and many companies provide alternatives to animal products.