A program is a collection of interrelated and coordinated projects. It is at the highest level and belongs to the concept of a strategic level. 

It has multi-level project management, helping managers to form strategic directions and allocate resources at a macro level. At the same time, it supports hierarchical access control, and the project set and the sub-projects and projects below can be separated by privileges. 

As shown in the figure, the program has the highest level, under which one or more sub-programs, products and projects can be managed. Products can only be linked to the top-level program.