When to use does?

Excuse me, could you please clarify when exactly is the appropriate time to use the word 'does' in a sentence? I've noticed that it's often used in questions, but I'm not entirely sure of the specific rules or contexts in which it's most suitable. Is there a general guideline or rule of thumb that can help me determine when to use 'does' effectively in my writing and speech? I'd appreciate any insights or examples you could provide to help me better understand this grammatical concept.