What is the difference between a buffered channel and an unbuffered channel in the context of inter-goroutine communication?

An unbuffered channel blocks the sender until the receiver reads the value, and vice versa — the receiver blocks until a value appears. This ensures synchronization between goroutines.

A buffered channel has an internal buffer of fixed size. The sender can send multiple values in a row without blocking until the buffer is full. The receiver can read values from the buffer without waiting for the sender, if the buffer is not empty.

Example:

ch := make(chan int)        // unbuffered
chBuf := make(chan int, 2)  // buffered with 2 elements

// ch <- 1  // will block if there is no receiver
chBuf <- 1 // will not block until the buffer is full

Thus, buffered channels allow more flexible synchronization management and can improve performance by reducing the number of blocking operations.