This is the 669th most frequent German word.
ändern
To change or modify.
The word 'ändern' refers to making a change to something, specifically altering or modifying it.
Ich möchte mein Passwort ändern.
I want to change my password.
Here, 'ändern' is used in the reflexive form 'ändern sich', indicating that the subject is undergoing change.
Die Farben des Gemäldes ändern sich mit der Beleuchtung.
The colors of the painting change with the lighting.
In this instance, 'ändern' conveys the action of revising or improving something purposefully.