The way you act towards other people can be categorised into three types of behaviour: Passive, Aggressive and Assertive.
If you tend to act passively then you may be seeking to avoid conflict, often at the expense of your own needs.
If you tend to act aggressively, you may go to the other extreme and escalate conflict in an attempt (not always successful) to get your own needs met.
Most people would agree that usually it is best to avoid both these extremes if you can and to act assertively – to express your own needs and wants, not to hide them, but to do so in a way which is reasonable and which allows others the opportunity to communicate their wishes and feelings too.
If you are in a relationship with someone or in a work situation where you feel that your needs are not being met or that the other person is acting in a way which you don’t like, then it will usually be helpful to express your feelings and thoughts to them assertively rather than to conceal them passively or to express them too aggressively.