what is the difference of sinus and cosinus

The sine of an acute angle in a right angled triangle is the opposite side over the hypotenuse.

The cosine of an acute angle in a right angled triangle is the adjacent side over the hypotenuse.

Maybe this will help.

Some Old Hags            Sine=Opp/Hyp

Can't Always Hide         Cos=Add/hyp

Their Old Age               Tan = Opp/Adj