Now that we understand the differences between Custodial and Non Custodial Wallets, let's talk about how those differences impact the accessibility & ownership of your Bitcoin.
You've most probably seen the words "Not your keys, not your Coins" somewhere on Social Media or heard it on a Podcast & it refers to the distinction between Custodial vs Non-Custodial Wallets above.
Your keys are whats called your "Seed Phrase", a collection of 12 - 24 words unique to your Bitcoin Wallet which can be seen like the pin code for your ATM Card or the Password to your GMail Account.
One of the main differences between Custodial & Non-Custodial is that a Custodial Wallet/Service never gives you your Seed Phrase, effectively tying you to them & their service in the same way as you are tied to your Post Office who actually own the Postal Box you are renting. Remember, it is Custodial & so is your Bank Account, as are the Bitcoin Wallets you have on your phone/computer which don't give you access to your Seed Phrase.
You don't own them or the way to access them, you merely have access to them. Access which can be revoked by the actual owner at anytime & for any reason they see fit.