Solana keypair as Identity explain by and for a beginner

In Solana, our identity is checked with a keypair: a public key, which is your address (a Solana address is a 32-byte Ed25519 public key encoded in Base58—for example, 14grJpemFaf88c8tiVb77W7TYg2W3ir6pfkKz3YjhhZ5. Base58 is chosen deliberately because it removes visually ambiguous characters like 0, O, I, and l), and a private key, which is the proof of ownership (called an "on-chain identity"). Unlike in Web2, where your identity is scattered across dozens of services—you have a username on Git