Summarize this article:

All baby formulas are regulated and, in general, every baby formula contains basically the same combination of protein, fat, carbohydrate, vitamins, and minerals, which closely mimic that of human breast milk. The difference between the formulas is the sources of the proteins and carbohydrates that are used. There can also be some variation in the sources of the other main components. Some parents may prefer not to feed their baby a formula that has a particular nutrient source, such as corn syrup, while others have no problem with it. Since the nutritional value is basically the same for all formulas, knowing about nutrient sources is a useful way to differentiate between baby formulas. Breast milk and formulas made from cow's milk have the same main carbohydrate, which is lactose. However, there are lactose-free and soy formulas for babies that are lactose intolerant or being raised as vegans. These, and other specialty formulas, contain various types of carbohydrates that might include sucrose, modified corn starch, corn maltodextrin, or corn syrup solids. Most formulas have cow's milk as a base and whey and casein are their proteins, but some other formulas are made from plant proteins and have a soy base. These proteins have a soy protein isolate that is easier for some babies to digest. Soy-based formulas are often fed to babies who suffer from allergies or digestion troubles when fed formulas with a cow's milk base. Vegetable based formulas are also popular with vegans because they want to avoid products that come from animals. The ingredients in organic formulas are sourced from organic produce and organic dairy. These ingredients are obtained without the use of chemicals such as pesticides, herbicides, and growth hormones. Some people believe that organic ingredients are more healthy for developing babies, and limit their exposure to harmful chemicals. Probiotic formula is formula that includes good gut flora, microorganisms that are meant to promote healthy digestion and regular bowel movements. Generally, these formulas are given to babies who suffer from diarrhea or generally weak immune systems. These bacterial cultures can strengthen the body's immune response and soften stools. The regulations for baby formula are strict about the nutrients that must be in the formula in order for the baby to grow and develop properly. However, these regulations do not restrict the addition of "other ingredients". Various brands add these ingredients for various reasons. One ingredient that is often added is various types of different nucleotides, which are supposed to help with the development of the immune system. These added ingredients are safe for the baby to consume and may help them develop, but they are more likely a way for the different brands to make their formula stand out.
Understand that the nutrients in most formulas are similar, but their sources can be different. Identify lactose in cow's milk formulas. Know that some formulas are made from soy. Understand the ingredients used in organic formulas. Be aware of probiotics used in some formulas. Look out for other ingredients that are often included in formulas.