So on this carbon, it attaches to the second carbon of the double bond. Or it can take pathway two, in which the lewis acid takes this H and attaches that H to the other side of the double bond to this carbon. So we can either take pathway one and form a tertiary carbocation, or we can take pathway two and form a primary carbocation. In each reaction, a different product is formed. So when our reaction takes pathway one, we form one product. When our reaction takes place and follows pathway two, we form a different product.