I see many people using the term "Rug pull" instead of "exit scam". Here I explain the difference.

So, what is a rug pull?

A rug pull, simply put, is when you have a staking pool that is governed by a flawed smart contract that no one is supposed to have governing access to. A good staking / yield farming pool will not even allow the people that created it to have some form of "back door access" that allows them to remove coins from it. The staking pool typically has a stablecoin or a governance coin like ETH or BNB as a trading pair. Without the stablecoin or the governance token in the pool, then the token would have zero value or near-zero value because these are usually put on decentralized exchanges. A "rug pull" is when the dev team or a hacker pulls out all of the stablecoin or the governance token. This means people who buy the token(s) in question see the value of it go to zero or near-zero. If you bought that token, then a real life example is to own 1000 shares of Google stock (altogether worth roughly $2,300,000) suddenly fall to pennies apiece or become altogether $00.00. You still have those things you paid for, but the person in charge of making those things more valuable ran off with your money and everyone else's without delivering a thing.

What is an exit scam?

An "exit scam" is a term people came up with back in the ICO craze of 2016/2017/2018. This was much simpler: you would send Eth / BTC / USDT / Whatever coin here, then you would be "promised" some coins in return. A "rapid" exit scam would be the dev team deleting their telegram, discord, fb, twitter, etc. and then saying nothing. However, there would also be what another user coined a "soft" exit scam. You see people send millions of USD of crypto to a dev team that is trying to make their own crypto, and they post news and updates regularly but here and there you see developers / employees leave the team slowly or they under deliver while spending lavishly.

I hope you learned something useful today.

EDIT: In Summary:
Rugpull, the coin goes to zero because the dev team pulls all of the liquidity from a decentralized exchange.
Exit scam: the coin goes to zero because the dev team ran off with funds that were supposed to be used for developing the coin. Their community sees that they've been abandoned, so they dump all of their coins wherever they can.