A control freak is someone who has a very strong desire to control the behavior of others, even in situations where it isn't appropriate. Sometimes these people only exhibit this behavior in certain contexts, like in a particular job, but others may continue bossing people in every aspect of their lives. Generally, they are experts at controlling others and they have many different methods of exerting that control. Sometimes control freaks are very successful in life, but it can be difficult for others to cope with them, and their attitudes can lead to severe difficulties in personal relationships.
It's fairly common for controlling individuals to act like aggressive bullies. A person like this may yell at others and try to intimidate, sometimes even relying on physical intimidation. Others control people through indirect methods like manipulation or subtle coaxing and trickery. Many control freaks need the feeling of direct control because it enhances their own personal opinion, so they may rely on the more aggressive methods. Others are content to know that they secretly control the behavior of the people they encounter.
In some cases, the motive for controlling people is actually fear. The person may worry that if other people are allowed to make decisions, they could make mistakes and mess everything up. These fears sometimes cause control freaks to interfere in anything that could have direct consequences in their lives. This is an especially common problem in the workplace with certain managers who are unwilling to let anyone else make decisions.
Another thing that can lead to bossy behavior is a lack of self-worth. In this case, the control freak is using his control of others as a way to create a high self-opinion. If he can make other people do his bidding, then he might think of himself as a more special person. Some control freaks will do anything they can to remain in charge so that they can maintain their own illusions of superiority.
In many cases, a control freak has a lot of knowledge and may deserve some level of deference from others. People with control issues sometimes go to a lot of trouble to develop expertise in a particular field just so that they'll never have to take orders from anybody. In some cases, this can actually be a problem for the control freak because he might ignore valid opinions from others due to fear of looking less knowledgeable.