I’ll do my best to make it simple:

A channel is basically a bitcoin transaction that opens a connection to Phoenix and lets you send the BTC over Lightning, so you don’t need the more expensive on chain transactions after you have it in a channel. But you have to *start* this channel by sending an on chain transaction. This channel has BTC in it “as collateral” in a sense, so payments can be sent and received in lightning within that amount. Think of it like bandwidth. If there isn’t enough, you need another bitcoin transaction to update it. Let’s say your bandwidth is 1,000,000 sats, well then that means you can receive or send up to that much *without* having to pay those fees again, because that 1mil sats can be sent with lightning.

If you want to see your channel you can go to “settings” -> “payment channels” (under advanced if you scroll down a bit) and you can see the amount. Your balance is on the left, the max is on the right.

After getting this channel, you can now pay out as much as you have all over Lightning (tiny fees), and there will be some extra Phoenix has added as bandwidth for you to receive. But if you receive a bunch more without paying any out, you may have to update your “bandwidth” again.