**Conditional tense**


https://www.englishpage.com/modals/could.html


As per the source

**"Could" is a modal verb used to express possibility or past ability as well as to make suggestions and requests. "Could" is also commonly used in *conditional* sentences as the conditional form of "can."** It is used in Past, Present and Future tense.

In **If you could travel anywhere in the world, where would you want to go?**, could is being used as the conditional of 'can'. 

https://learnenglish.britishcouncil.org/english-grammar/will-or-would

**As per the source *would* is used to talk about hypotheses, about something which is possible but not real:**

It is being used to talk about the result or effect of a possible situation:
EG: It would be very expensive to stay in a hotel