What is the difference between a dot and tie in music?

dot increases duration by one half. Since an eighth note is half the duration of a quarter note, we will substitute it for the 1/2 symbol. Ties merge multiple notes of the same pitch. They are used to let the duration of a note travel across barriers (such as the measure line in this example).

Explanation:

soft,hard and rough for soft would be a pillow or a stuffed animal hard wood floor or a table rough paint