The difference between a free-form and a structured information manager needs some explanation. A free-form product allows text to be created, transferred, or imported from another product without any particular form being imposed on the information. It is typically ASCII text. The free-form information manager would also be expected to have a means by which its items can be retrieved, typically by string searches.
The three main functions of any information manager are (1) collection (2) storage and organization and (3) retrieval of data. The difference between the "free-form" and the "structured" products has to do with the second function - the storage and organization of data.
The free-form managers described here both use a simple means of organization, based on a container metaphor: the items that are created are stored in containers, and these containers may also be contained within other identical containers. In Info Select, the containers are called "topics"; in Zoot, they are called "notebooks". These assignments are mandatory; each item has to be found in at least one such container. Each product also has one or more other categories to which items may be assigned; essentially, these represent different containers, and their use is optional. Info Select provides tabs representing "folders" to which items may be optionally assigned. Zoot provides optional file types and colors, both of which can be used to designate items and to group them together, independent of their assignments to notebooks.
With these products, the assignment of an item to a container is a simple one-dimensional connection: a note is simply assigned to (contained in) a notebook or topic. For any given note and any given notebook, the realtionship between the two is a simple binary value of 1 or 0; the note is either contained in or not contained in the notebook.
(Zoot is more sophisticated than Info Select in this basic categorization function, in that it allows a note to be contained in one or many notebooks at the same time. A note in Info Select, by contrast, may reside in one and only one topic. Zoot also has a very sophisticated set of scripting tools for making or breaking assignments of notes to notebooks, based on either text matching or other criteria.)
The structured information managers like Agenda, Ecco, and Commence, and the true database programs themselves, add a second dimension to the categorization of items. Following the lead of full database programs, they have the capability to assign values to categories for each item. Items are not simply contained in categories; they are assigned a value within those categories. (Sometimes the second dimension of information is not needed, and the category simply has "yes" and "no" or a checkmark as the only possible entries.)
If the program is used to keep track of commercial real estate, as an example, it might include a reference to a three-story office building, built in 1969 at a cost of $578,000, and located in Southfield, Michigan. It might start with the item "Jenison building", to which would be assigned the following values:
| Cost | Location | Year built | |
| Jenison building | $578,000 | Southfield, Mich | 1969 |
The program might include 15 or 1,500 similar entries. The items could then be sorted and/or filtered according to the values assigned in these categories -- ranked by cost, or by location, or by year built.
The free-form information managers do not have the capability to store such detailed information. Their purpose is directed more to the storage and organization of text than to the assignment of values to their notes, and the simple categorization approach suffices for most purposes.
These examples demonstrate that some types of data need the structured approach, while others are better handled with the one-dimensional assignments offered by "one-dimensional" managers like Zoot and Info Select.