Private Key
256-bit number giving full control over a crypto address. It is top secret.
Private key: cryptographically secure random number. Whoever knows it controls the address = owns crypto. Format: 64 HEX (0x...) or WIF. Seed phrase (12-24 words) generates keys deterministically. NEVER share, online, screenshot. Cold wallet keeps it offline.
In plain words
A very long (256-bit) string that gives full control over your crypto address. Whoever knows your private key can take everything sitting there. NEVER share it, type it online, or screenshot it. There's no 'forgot password' in crypto. Lost key means lost crypto.
Example
Example private key: 0x4c0883...796... (NEVER share yours!). Public address: 0x6E9...8a (derived from key). Share address (others can send). Private key stays ONLY with you.
Also known as: private key, klucz prywatny