Will there be duplicates?

Question

Search Engine Optimization

I decided to change the CNC in wordpress. Changed and made a redirect through functions.
Will there be duplicates? If not, then it turns out that they will temporarily hang in the index of the page on the old links until they are updated to the new ones? Or do you still need to specify another redirect?

Answer 1

It is better to make a 301 redirect from old pages to new ones.