Google is not a fan of duplicate content and there is good reason for it. But in some instances there is a need for it. For example:
A site may be replicating content from others
Just one product may share merchandise info that is identical across the numerous sites that it’s recorded on
A site might have shifted to both domain names share precisely the same content and a new web domain name
Multiple session IDs are created due to individual IDs being assigned to new internet visitors
When you have duplicate content online, Search engines pick one over another and will be difficult for search engine robots to decide which is better. The ultimate content exhibited may or may not be the variant you would like. You don’t need to leave that up to the search engines to determine. You can have control over the content that’s listed in the SERPs through optimization techniques that are proper on page.
Another reason to avoid having duplicate content is to not have your site appear as a spam site due to attempts to drive more traffic through content taken from other sources. Though Google has stated that they do not have a penalty for duplicate content, they aim to only list original content that’s value that is great, by ranking in the SERPs plus they reward these content creators in sort.
How to avoid duplicate content issues?