diff --git a/concurrency/iterator_error_handling/main.go b/concurrency/iterator/iterator_error_handling/main.go
similarity index 100%
rename from concurrency/iterator_error_handling/main.go
rename to concurrency/iterator/iterator_error_handling/main.go
diff --git a/concurrency/iterator_sem/main.go b/concurrency/iterator/iterator_sem/main.go
similarity index 100%
rename from concurrency/iterator_sem/main.go
rename to concurrency/iterator/iterator_sem/main.go
diff --git a/concurrency/pipeline_from_book/main.go b/concurrency/pipeline/pipeline_from_book/main.go
similarity index 100%
rename from concurrency/pipeline_from_book/main.go
rename to concurrency/pipeline/pipeline_from_book/main.go