Keto and LCHF have the same foundation. The only real differences are the amount of carbs per day and whether or not your aim is to be in full ketosis all the time. A lower carb diet is considered to be anything below roughly 130g of carbs per day whereas the general consensus for Keto is less than 20g carbs per day though some would say less than 25g per day. Hope this clarifies for you.