is weak acid and dilute acid the same.why

No they are not the same because a weak acid is an acid which is weak in its nature.Eg acetic acid present in vinegar that we use in homes whereas a dilute acid means a concentrated acid or a strong acid that has been made weak by adding water to it.

Whenever water is added to a concentrated or a strong acid it gets diluted that is becomes less acidic as compared before and this process of adding water to a concentrated acid that is a strong acid to make this strong acid into a less concentrated acid or less strong acid is called dilution.

So you cannot say that a weak acid and a dilute acid are same because a weak acid is weak in nature but a dilute acid is a strong acid which has been made weak.