The nature provides an increase to one of your Pokemon's stats and a decrease to another. Since your Pokemon's nature is Hasty, it will have an increase in Speed and a decrease in Defense.
The characteristic indicates which one of your Pokemon's stats has the highest IV and gives a hint as to what that value is. In this case, the characteristic is "Good perseverance", meaning your Pokemon's Speed IV is your Pokemon's highest IV, being either 4, 9, 14, 19, 24 or 29.
Hope I helped. :)
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