Difference between pot equity and EV?

[PequDios]

It seems to my that pot equity and EV is just the same. Pokertips.org has this to say about EV:

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Expected Value is how much you expect to win on a hand in the long run. For example, suppose you have a 50% chance of winning a $12 pot. Sometimes you will win $12 and sometimes you will win $0. However, your expected value is $6. The way you calculate expected value is (percentage chance of winning * pot size).

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and on pot equity it says:
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Pot equity is your expected value from the pot. Suppose you have a 20% chance to win the pot. There is $100 in the pot. Thus, your pot equity is $20

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It's the same mathematics. But what's the difference between EV and pot equity?