Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format using 64 different characters: A–Z, a–z, 0–9, plus "+" and "/". The "=" character is used for padding.

It is commonly used for encoding data that needs to be stored or transferred over media designed to handle textual data. This ensures that the data remains intact without modification during transport.

Common use cases include embedding images in HTML/CSS, storing complex data in JSON, and transmitting authentication tokens in HTTP headers.