Guidance to using Blockfi.

Hello all. So I've been mining eth for quite some time now and have been holding on to it waiting to sell it and make a large purchase, that's why I even got into mining. That aside, I am wondering what exactly Blockfi would do with my current holdings.

Now, several of my friends have converted their entire savings accounts to stable coin through Blockfi, attempting to take advantage of the high interest rates, 8.6apy. And the same seems to be true with eth stored in their platform. I'm wondering however, if I were to deposit a large sum of eth to Blockfi, is that considered staking? And would it be available to withdrawal on demand need be? Or would it simply be me storing my eth in their hot wallet and attempting to feed off their advertised 4.6apy? Any insight is appreciated. I have a couple usd worth of eth in their right now from 20 usd I deposited with them awhile ago just it make an account, and it seems that I can withdraw it now if I wanted, but I am wondering if the amount grows, do the stipulations for withdrawal change? If anyone has any advice please let me know, and if there is somewhere better to post this, let me know, thanks for reading.