You can join (concatenate) binaries (including strings) and lists:
iex(1)> [1, 2, 3] ++ [4, 5] [1, 2, 3, 4, 5] iex(2)> [1, 2, 3, 4, 5] -- [1, 3] [2, 4, 5] iex(3)> "qwe" <> "rty" "qwerty"