What are the different types of channels and their use cases?

Channel Types and Patterns: • Unbuffered: Synchronous communication • Buffered: Asynchronous with capacity • Directional: Send-only, receive-only • Select with channels for multiplexing Patterns: • Fan-out: Distribute work • Fan-in: Collect results • Pipeline: Chain operations • Worker pools: Limit concurrency • Cancellation: Context-based Example: // Directional channels func sender(ch chan<- int) { ch <- 42 } func receiver(ch <-chan int) { v := <-ch } // Pipeline func pipeline() <-chan int { out := make(chan int) go func() { defer close(out) for i := 0; i < 10; i++ { out <- i * i } }() return out }