When you enter a query, Z instantly searches all your text files and dynamically generates a mini-directory of related topics specifically suited to your subject. It's like having your own personal directory service that lets you zoom in, anywhere you want to go . Created and maintained by editors. Costly and labor intense process limited by the human factor and associated costs. Spiders and automatic index methods are used to create, add and maintain links in large database.
Indexing is less precise but more affordable.
Permits fee based, real-time submission and maintenance. No navigation tools available. Knowledge of subject required prior to search. Navigation is intuitively easier and more advanced than any other search solution. Refinement of a search is easy and self-evident.