The objects manipulated by ConceptBase are persistently stored in a collection of external files, which reside in a directory called application or database. The actual directory name of the application is supplied as the -d parameter of the command CBserver.
The -u parameter of the CBserver specifies whether updates are made
persistent or are just kept in system memory temporarily. Use -u
persistent for a update persistence or -u nonpersistent for a
non persistent update mode 
.
The application can be modified interactively using the editor commands TELL/UNTELL. Another way of extending applications is to load Telos objects (expressed in frame syntax) stored in plain text files with the extension *.sml. Call the menu item Load Model from the File Menu to add these objects to the knowledge base (KB). In our example the application (directory) Employee was built interactively and can be found together with files containing the frames constituting the example in the directory
CB_HOME/examples/QUERIES
where you have to replace CB_HOME with the ConceptBase installation directory. The
following files contain the objects of the Employee example expressed in
frame syntax: Employee_Classes.sml, Employee_Instances.sml,
Employee_Queries.sml. An alternative to interactively building an
application is to start the server with an empty application (-d
newfile 
) and then add the objects in these files
by using Load Model. Note, that the *.sml extension may be omitted.
During the load operation of external models, ConceptBase
checks for syntactical and semantical correctness and reports all errors to
the history window as it is done when updating the KB interactively using the
editor. This protocol field collects all operations and errors reported since the beginning of
the session.