Using Docker version of Lightning Network daemon to gain understanding In trying to understand the Lightning Network further. To do so, I was looking at the link below (it shows how it is being used with Docker):
https://hub.docker.com/r/cdecker/lightning-ci/

Based on the information in the link, I had questions.


STEP 1: # Returns an address  cli/lightning-cli newaddr
^^^^ Ques: Is this a new address created on LIGHTNING NETWORK? Is it on the BITCOIN NETWORK? Is it in "No-Mans-Land/Purgatory"? Where
is the Private-Key? Can many addresses be created?
STEP 2: # Returns a transaction id  bitcoin-cli -testnet sendtoaddress  
^^^^ Ques: So, if you forget / lose this address (after sending money to it), you are out-of-luck? Also, "bitcoin-cli" commands are
executed under the "btcd" BITCOIN dameon?
STEP 3: # Retrieves the raw transaction  bitcoin-cli -testnet getrawtransaction 
STEP 4: # Notifies lightningd that there are now funds available: cli/lightning-cli addfunds 
^^^^ Ques: It is at this point the funds are actually added to the LIGHTNING NETWORK. I take it that the funds are associated with
the  created in STEP 1 above?


TIA
The documentation you are following is using the bitcoind wallet, so the address generated in Step1 will be derived from your bitcoind master private key. 

Checking the current c-lightning documentation, this seems outdated, step 3 and 4 are no longer needed.


Q1: this returns an address from the bitcoind wallet
Q2: you send a bitcoin transaction from any wallet you like, here the local bitcoind (Bitcoin Core) node is used.
Q4: here, you notify lightningd to use the funds when opening channels. But no channel is opened and thus no funds are committed to the Lightning Network yet. (as mentioned, seems obsolete now with current release)