The catalog is fundamental to JEAN. It allows you to store and access your information in the most convenient form for your business. The catalog holds information in nodes in a tree-like structure. At the very top of the tree is a special node, called root. When you bring JEAN up for the first time, this is all you will see, until you have entered some information of your own.
Nodes are used to represent the entities you are interested in. A node can be a single item or it can be a category or group. A category is used where you want to classify items. For example, if you have a number of clients you may want to classify them according to the area of the country they live in. A group is used where you want to put a number of items together usually in order to carry out some task on them. For example in multimedia you may want to group together particular music tracks so that you can play them all.
A category can contain other categories or groups or it can contain items. A group can contain other groups or items, but not categories. In this way the tree-like structure is created. However, it is possible for an item to belong to more than one category or group. That is, an item can have more than one parent node. This means that the catalog structure is a directed acyclic graph (DAG) which is more powerful and flexible than a simple tree.
It is possible for an item in one catalog to cross-reference an item or items in another catalog. For example, an appointment in the calendar may cross-reference or link to an entry in the addressbook. The DAGs, representing the catalogs, and the links between them, make up the JEAN network.
The default icons are a cat to represent a category, a filing cabinet to represent a group and a smiling face to represent an item. Clicking on a plus sign next to a category or group will expand it one level and clicking on the minus sign will close it up again.