No real difference. Just the price. Lansinoh is usually more expensive because it's being marketed at a specific use... breastfeeding. You can usually get 100% lanolin in a tube from your pharmacist (some keep it in stock, others need to order it) for cheaper. A lot of people use the Lansinoh because they already have it around the house. :LOL Liquid is easier to work with because you don't have the "congealing" issue when the water cools down.
lansinoh is carefully refined so that babes suckling on it dont consume wool fiber, which in large doses can cause genuine wool allergies. if a mama uses lanolin on her breasts a lot, this is the safest lanolin to use.
that is the only difference. i prefer plain lanolin, which is usually thinner in consistency and much less expensive.