Empty structs are used in Go as a unary value.
// anonymous empty struct type
empty := struct{}{}
// named empty struct type
type emptyStruct struct{}
empty := emptyStruct{}
The cool thing about empty structs is that they're the smallest possible type in Go: they take up zero bytes of memory.

Later in this course, you'll see how and when they're used: it's surprisingly often! Mostly with maps and channels.