They are the same. But sometimes you can use one of them but not the other. E.g. Strike a match (light a match). You can't say hit a match. But you can strike or hit somebody. Strike a chord - this is idiomatic and means that something sounds familiar or you understand personally what somebody said/feels like. "It struck a chord with me when she was talking about how much she loved walking in the mountains." There are a lot of idioms like this with strike or hit where you use one but not the other. Strike out, strike up a relationship...