They have completely different meanings: "Strike" means to hit. For example, "He struck (past tense of "strike") the match against his boot to light it." "Stroke" means to rub or massage. "The woman was stroking (past progressive form of "stroke) the baby's head to calm his cries." I hope my explanation has been clear. Let me know if you have any more questions or would like to see more examples.

One has an 'i' and the other has an 'o'! But seriously - in what context? Both words have many different meanings, and I can't think of one where the meanings are similar, that might be confusing to you.