To conduct ones life in a professional manner is to be fully capable, competent and qualified. If follows that professional behavior is being prompt, prepared, able to find solutions, to perform all tasks as expected, to be infallible, to meet or exceed an average persons expectations. Orderly and clean in speach, and deed and be a standard bearer.
Professional manner is the practice of doing a better job than an amatuer would. To repair a car in a professional manner would be to expertly diagnose the problem, repair the problem in a cost efficient manner, and to complete the repair in a timely manner.
Professional behavior is 1) maintaining a professional manner 2) acting/behaving in a manner that enhances the reputation of your enterprise 3) avoiding exhibitions of non-business related attitudes.
Professional behavior means being able to project the image suited to your workplace. Through many channels including communication, dress code, personal boundaries and confidentiality.
Being able to look beyond the initial needs of the business and dollar sign to know what the business needs. This means that a business will generally work towards a common goal if monitored
Professional behavior is another concept created by corporatism in order to manipulate professionals into behaving as robots without regard for any personal code of ethics. This type of professional behavior has nothing to do with whatever an individual "professes" to know in any particular field. Indeed, the ethical code to adopt is that listed in the policies of the institution without regard for sex, culture or religion. All professionals must conform to this institutional code in order to maximize profits, maintain the hierarchical power structure and ensure the maximum exploitation of workers. At work, professionals are expected to NOT behave as humans; but rather to wear a mask, thereby reinforcing whatever "professional" egotistical image has been implanted in their minds throughout their lives by a society also engineered by corporatist ideals.
If you are a freelancing, critical thinking, intelligent individual with integrity it would be next to impossible to behave professionally...
To act like an adult with manners
To me being professional means that you make a deal not to appear human to others and they to you - so that you can each partake in pure self interest without guilt or fear of repercussion. I ignore it.