You use the SEQUENCE step to build a set of steps that you want to treat as a group. Steps in a group are executed in order, one after another. By default, all steps in a flow service, except for children of a BRANCH step, are executed as though they were members of an implicit SEQUENCE step. That is, the flow steps execute in order, one after another. However, there are times when it is useful to explicitly group a set of flow steps. The most common reasons to do this are: