Bitcoin relies on public key cryptography to secure transactions, with two essential components:

1. Public Key (Your Bitcoin Address)
Acts like a bank account number; it’s shared publicly so others can send you Bitcoin.

Derived from the private key using cryptographic algorithms.

Can be safely shared without compromising security.

Usually appears as a shorter, hashed version called a Bitcoin address (e.g., 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa).

2. Private Key (Your Secret Password)
Acts like a password—it proves ownership of Bitcoin and authorizes transactions.

Must never be shared—anyone with it can control your funds.

Typically, a 256-bit number, often represented as a 64-character hexadecimal string or a 12/24-word seed phrase.

Used to digitally sign transactions, proving you own the Bitcoin being spent.

Key Security Rule:
Public keys can be shared freely.

Private keys must be kept secure—losing them means losing access to your Bitcoin, while exposing them risks theft.

In short:

Public Key = Receiving Address (Shareable)

Private Key = Spending Authority (Keep Secret!)