Along with loose and definitely, separate is one of the most commonly misspelled words in the English language. Separate can be an adjective or a verb. As an adjective, it means set apart, distinct, or not related. As a verb, it means to to set apart, to distinguish, or to divide.
Separate applies both to putting apart and to keeping apart: "In the darkness and confusion, the bands of these commanders became separated from each other" (Washington Irving).
Seperate is a misspelling of the word separate, and it should always be avoided. This mistake is easy to make, but seperate is not correct in any contexts. As you can see from this chart, the uses of seperate are so rare as to approximate zero—since at least 1800.