Like the shorthand flex property, the shorthand flex-flow property is used to declare both the flex-wrap and flex-direction properties in one line.

.container {
  display: flex;
  flex-wrap: wrap;
  flex-direction: column;
}

In the example above, we take two lines to accomplish what can be done with one.

.container {
  display: flex;
  flex-flow: column wrap;
}

In the example above, the first value in the flex-flow declaration is a flex-direction value and the second is a flex-wrap value. All values for flex-direction and flex-wrap are accepted.

Note: The flex-flow property is declared on flex containers.