What is the difference between buffered and unbuffered channels?

In Go, channels can be buffered or unbuffered, and this affects the behavior of sending and receiving data.

• Unbuffered channel — a channel without an internal buffer. The sender blocks until the receiver reads the value. Similarly, the receiver blocks if there is no value to read.

• Buffered channel — has an internal buffer of fixed size. The sender blocks only if the buffer is full, and the receiver blocks if the buffer is empty.

Example of creating a buffered channel:

ch := make(chan int, 3) // buffer of 3 elements

Using buffered channels is useful when you need to smooth out the speed difference between sender and receiver, allowing the sender to continue working until the buffer is full.