Encoding/Decoding:

• Base64: Binary-to-text encoding scheme, commonly used for data transmission
• URL Encoding: Converts special characters to percent-encoded format for URLs
• HTML Encoding: Escapes special HTML characters (<, >, &, etc.)

String Operations:

• Add Slashes: Escapes quotes and backslashes with backslash (for SQL, etc.)
• Strip Slashes: Removes backslashes from escaped strings

Hash Functions:

• MD5: 128-bit hash (not cryptographically secure)
• SHA-1: 160-bit hash (deprecated for security)
• SHA-256: 256-bit hash (secure, widely used)
• Note: Hash functions are one-way only - you cannot decode them