Containers are groupings of forums. For example Engineering may be a
container. Inside that container there would be a Math forum, Mechanical
Engineering forum, etc.
Go to Content management->Forums
Click on the Add container tab
Under Container name enter the name you would like for the container.
Enter a description of the container.
If you would like to place this container inside another container or forum
under Parent choose where the container should appear.
To order the containers you can choose the weight. Higher weight will go to
the bottom. Lower weight will put it towards the top. If two items are the
same weight then they will be sorted alphabetically.