Proffessor:

The meaning of the word professor (Latin: professor, person who professes to be an expert in some art or science, teacher of highest rank[1]) varies. In some English-speaking countries, it refers to a senior academic who holds a departmental chair, especially as head of the department, or a personal chair awarded specifically to that individual. For example,
in the United Kingdom, Ireland, South Africa, Australia and New Zealand it is a legal title conferred by a university denoting the highest academic rank, whereas in the United States, Canada and Hong Kong, the term professor generally is used as a form of address for any lecturer or researcher employed by a college or university, regardless of rank. However, in some institutions, the term is used only for academics who are tenured or tenure-track. In some countries, e.g. Austria, Brazil, Democratic Republic of the Congo, France, Romania, Slovenia, Croatia, Serbia, Poland and Italy, the term is an honorific applied also to secondary level teachers.
Professors are qualified experts, of the various levels described above, who may do the following:
• conduct lectures and seminars in their field of study (i.e., they "profess"), such as the basic fields of science, humanities, social sciences, education, literature or the applied fields of engineering, design, music, medicine, law, or business;
• perform advanced research in their fields.
• provide pro bono community service, including consulting functions (such as advising government and nonprofit organizations);
• teach campus-based or online courses with the help of instructional technology;
• train young or new academics (graduate students);

carry out administrative or managerial functions, usually at a high level (eg. Deans, Heads of Department, librarians, etc.).