the word 'dressed' can be used as a verb to refer to the act of putting on clothes. It is used as an action that someone performs on themselves (e.g. 'She dressed quickly') or can be used to describe the action of someone else helping someone else to dress (e.g. 'He helped her dress for the party').
when used as a verb, 'dressed' always refers to the action of putting on clothing. It is used to describe someone putting on clothing for any purpose, in any context, and is often used to describe the process of getting dressed for special occasions.
1. She dressed quickly and left her house for the dinner party.
2. We all dressed up for Halloween and went trick-or-treating.