As mentioned above, Simics's configuration system is object-oriented. A Simics object is instantiated from a Simics class. The core of Simics defines some useful classes, but most of the classes (processors, device models, statistic gathering extensions) are provided by modules that are loaded by the simulator when requested.
For example, the x86-p4 module defines, surprisingly, the x86-p4 class. Note that a module may define several classes. Since modules advertise the classes they define, Simics can load modules transparently as objects are instantiated.
A class defines attributes that represent both the static and dynamic state of the instantiated objects. The static state includes information that doesn't change during the simulation (like a version number in a register) while the dynamic state covers the part of the device that are affected by the simulation (registers, internal state, buffers, etc.).
Let us take the example of an x86-p4 processor and have a closer look:
As you noticed, attributes may be of various types. A complete description is available in the next section.