Theoretical model calculations of magnetic elemcnts in the photospheric layers of solar active rcgions are cornpared with the results of observations. Emphasis is placed on small scale magnetic elements and an attempt is made to provide an
overview of the contributions that the current state of theory and observation can make to answering the following questions:
What is the field strength and the magnetic field structure of a magnetic element? Are magnetic elements inclined with respcct to
the vertical? Do magnetic canopies exist and how can they be explained? What are the diameters of magnetic elements? What
kinds of mass motions are present in magnetic flux concentrations and what role do they play for their structure and energetics?
How high is the temperature in magnetic elements and what are the underlying heating mechanisms?