Saturated fats are produced from animal products - meat, dairy, eggs and are also found in some plant-based sources such as coconut and palm kernel. Examples containing saturated fats include: butter, palm oil, coconut oil, lard, meat fats, eggs. They raise total cholesterol levels and LDL (bad) cholesterol. Whether they impact your physiology negatively depends on the individual. You should ask your doctor whether you should avoid these fats. Note that for cooking, saturated fats (particularly butter or coconut oil) are actually the best oils to use as they have a very high heat threshold.
Trans fats, however, are 'special' saturated fats, formulated to extend the shelf life of processed food - breads, cookies, meals, fries ... that come in packages or are frozen. They are also used to created products that stay hardened such as in margarines. Trans fats not only raise total and LDL cholesterol levels, but they lower the "good" cholesterol, HDL, levels. You should read food labels carefully to see if products contain trans-fats. Apparently trans-fats are also used by many fast-food and other restaurants and are reputed to cause diarrhea. Fried foods typically also contain high amounts of trans fats. Trans fats should be completely avoided as they contain high amounts of free radicals that cause cell damage, and can contribute to chronic inflammatory conditions such as Arthritis as well as heart disease.