So if i put the Ledger in my computer and with the wallet on my pc i sent it to the wallet on the Ledger usb then they the coins are gone from my computer and stored on the usb?
the coin or bitcoin is not a physical thing like fiat to transfer from one place to another.
a bitcoin wallet is a place to keep they keys. these keys are used to spend bitcoin, bitcoin which exists in form of transaction outputs stored on the blockchain and blockchain is held by every person around the world who is running a full node client.
so in short you keep the keys on Ledger or paper wallet, etc and then use that key for spending which is known as creating a transaction and signing it.
(i hope i didn't make it more confusing)
My safest way to keep my bitcoin is to keep my password private to others and to keep it in my wallet. And putting some codes in my wallet.