Ideas for using a database? Any good opensource ones?

Well, I’ve never used a database yet. So always trying to better organize myself, I figured it was about time I learned how to use one.

Does anyone have any good ideas as to what to use one for?

Recomend a good open source program?

I don’t know if this is possible, but I would like to search my database of recipes (when I create one lol) based upon ingredients I have already lying around, can I do this?

Has having/using a database made your life easier and/or more organized in anyway.

I can’t appreciate the value of one yet (if there is one), and would be grateful if someone could give me their opinion on them.

Thank you