Tries store strings with shared prefixes.
Each node represents a character, paths spell words. Core Operations: - Insert: , create nodes along path - Search: , follow path, check isEndOfWord - Prefix: , like search but no end check Key Patterns: - Wildcard search with DFS - Word dictionary with isEndOfWord flag - Autocomplete with prefix traversal When to Use: String prefix problems, dictionary lookups, autocomplete systems.
Time: per operation. Space: worst case.