Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The TBox (A) includes classes (kinds of things), properties (the possible relationships between classes and instances of the classes), and assertions about the classes and properties. The ABox (B) represents instances of the classes represented in the TBox and assertions about those instances. For example, an instance of femur in a frog specimen is 1.2 cm long. Image credit: Photo from National Museum of Natural History, Washington DC.
