I get this question a lot at craft shows and I sometimes have a hard time explaining the differences in a simple and quick way - so hear is the long answer.
Thanks to the awesome blog called The Little Herbal for such a clear and succinct explanation. I'm a big fan of her blog. I've made some additions to her commentary. My comments are in brackets unitalicized.
What is the difference between a Lotion vs. Cream vs. Salve vs. Body Butter?
Salve- A salve is simply a combination of oil(s) and beeswax. Beeswax is melted with the oil and then when it cools it will harden into your desired consistency. It can also have other things added to it (essential oils, butters, vitamin E, etc.) but it does not contain water. This gives it a long, stable shelf life (without added preservatives. The beeswax acts as a preservative in this case). A Salve is similar to a balm which can be the same type of ingredients or include the addition of a butter such as cocoa, shea or mango butter for example.
Lotion: A lotion is created when you take oil & water and blend it together using an emulsifying agent, typically emulsifying wax or beeswax. Lotion usually has a higher concentration of water to oil (70% water, 20% oil, 10% emulsifying agent). Depending on whether or not you use preservatives, lotions will have a shorter shelf life due to the high concentration of water. (Lotions like creams are made with water and thus in order to have a stable shelf life, they either need to have preservatives added, or if you don't want to use a preservative, you need to store this at cool temperatures such as in the refrigerator in order to prevent the growth of yeast and bacteria. In which case they will last approx. 3-4 months.)
Cream: A cream is also created when you take oil & water and blend it together using an emulsifying agent, typically emulsifying wax or beeswax. Creams have a higher concentration of oil in them than lotions (45% water, 45% oil, 5-10% emulsifying agent), making them thicker, heavier and more moisturizing. (Like lotions, creams have water and thus need a preserving agent or should be stored in the refrigerator for a longer shelf life. You can make a cream with a lower percentage of water, and a higher percentage of oil. e.g. 15-20% water or hydrosol, 60-80% oils & butters, 10-15% emulsifying agent)
Body Butter: A body butter is created by blending natural butters like shea butter, cocoa, butter and/or mango butter. My body butter recipes usually tend to be a blend of butters and liquid carrier oils making them more malleable and easy to apply and absorb into the skin. (An example would be 60-70% butters and 30-40% oils)From: The Little Herbal NOTE: ratio's are in weight, not volume. -------------- I currently make both salves and butters for PLANTiful and will have several of them at craft shows & in my online shop. They are luxurious, made with rich moisturizing Alberta wildflower beeswax, handmade herbal infused oils, organic fair-trade butters such as, mango, shea, and cocoa. I also add healing essential oils in them for both scent and therapeutic properties. Whether you are looking for something for your face, your hands, or a little babe you know, I've got you covered!!