What Activate-Reveal an account refer to

Question

I have 5 questions related to two types of operations: Reveal/Activate

1. What we mean by ativate an account?
2. What we mean by reveal an account?
3. What's the difference between this two operations?
4. It is necessary to activate/reveal an account after it's generation by using a lib (eztz as examlpe) not the faucet.
5. Can we activate/reveal an empty account by an RPC call(s) by making someone else pay the gas for this operation(s)?

Thank you in advance.

Answer 1

These are very different operations...

1. activate_account is an anonymous operation that bootstraps the account with some coins purchased during ICO. So, this is for the ICO participants only. Or for the testnets' faucet.

2. reveal is a manager operation that shows everyone your public key, so that everyone can verify your signature in subsequent operations.

3. It's obvious =)

4. If you are not an ICO participant, you can't activate your account (but even if you are, it's still not necessary).
   As for reveal, you have to do it before sending your first transaction, origination or delegation (after your account is allocated).

5. Anyone can broadcast activate_account operation because it's an anonymous operation. Also, it doesn't spend fee or gas, so you can easily activate an empty account.
   But reveal must be only sent by public key owner. And it spends fee, so you can't reveal an empty account (actually, you can, but bakers likely won't include your operation into block, due to zero fee).