Assertiveness is the ability to stand up for yourself, to defend your opinion, to strive for something and fight for your rights without violence, with the respectful attitude to differences of opinion and freedom of expression. An assertive person is aware of her feelings, interests and needs and can express them clearly while taking into consideration others and their needs. Such a person can compromise when conflict arises, and they know their needs, interests, emotions, feelings and limits and don‘t hide them from others.
In summary, we can say that is assertiveness the ability to express own wishes and beliefs in a positive way, taking into consideration personal boundaries of our own or/and from the other(s).